DRD Solar Home
Systems (SHS) in
Myanmar: Status and
Recommendations
Report to the World Bank
Chris Greacen, Ph.D.
January 2015
This note reflects solely the views of its author, not necessarily those of the
World Bank management or Board of Directors.
Table of
Contents
Abbreviations .............................................................................................................................. v
1
Overview ............................................................................................................................. 1
2
Background......................................................................................................................... 2
2.1
Rural electrification and the DRD ................................................................................. 2
2.2
DRD’s solar home system program ............................................................................. 2
2.3
DRD’s solar home system specifications ..................................................................... 4
3
Scope and Methodology ..................................................................................................... 4
4
Research results ................................................................................................................. 6
4.1
Village selection process.............................................................................................. 6
4.2
Tendering process ....................................................................................................... 8
4.3
Findings from village visits ........................................................................................... 9
4.3.1
Allocation of solar home systems within village ..................................................... 9
4.3.2
Customer profile ................................................................................................... 9
4.3.3
Savings enabled by SHS .....................................................................................10
4.3.4
Usage patterns ....................................................................................................11
4.3.5
What happens when something breaks ...............................................................12
4.3.6
Technical assessment of DRD SHS performance and equipment quality ............12
4.3.6.1
Wiring ...........................................................................................................12
4.3.6.2
Solar Panel ...................................................................................................14
4.3.6.3
Charge Controller .........................................................................................17
4.3.6.4
Battery ..........................................................................................................19
4.3.6.5
Inverter .........................................................................................................21
4.3.6.6
Lighting .........................................................................................................22
4.3.6.7
Operation manual .........................................................................................23
4.3.7
DRD centralized systems .....................................................................................23
4.3.8
DRD battery charging station ...............................................................................25
4.3.9
Hire purchase SHS ..............................................................................................25
4.3.10
Privately purchased SHS .....................................................................................26
4.3.10.1
User-purchased SHS are common ...............................................................26
4.3.10.2
SHS shops....................................................................................................26
4.3.10.3
Typical user-purchased SHS have severe technical shortcomings ...............28
i
5
4.4
DRD SHS supply chain ...............................................................................................29
4.5
ICT and solar electricity in Myanmar ...........................................................................30
4.5.1
Solar hybrid systems to power towers ..................................................................30
4.5.2
Cell phone towers as anchor customers for village mini-grids ..............................31
4.5.3
Solar PV for charging cell phones ........................................................................32
4.5.4
Cell phone network to transmit mini-grid system performance data .....................32
4.5.5
Electricity purchases via “Mobile money” .............................................................32
Recommendations and points for discussion .....................................................................33
5.1
Policy, planning and regulation ...................................................................................33
5.1.1
Include NEP geospatial plan in village selection ..................................................33
5.1.2
Integrate sources of funding beyond DRD budget ................................................34
5.2
Technical ....................................................................................................................35
5.2.1
Revise DRD SHS specifications to safeguard reliability and sustainability; ..........35
5.2.2
Revise DRD SHS system design to improve efficiency, reliability ........................35
5.3
Financing and subsidies .............................................................................................36
5.3.1
5.3.1.1
Should there be user subsidies? If so what amount? ....................................37
5.3.1.2
Should there be subsidies for market development? If so what amount? ......37
5.3.1.3
none?
How should specifications be designed? Fixed capacity vs. service level, or
37
5.3.1.4
How to ensure long-term service follow-up ...................................................38
5.3.2
5.4
Trade finance .......................................................................................................38
Environmental and social ............................................................................................38
5.4.1
5.5
Redesign DRD SHS program to reduce subsidy amount, increase sustainability .36
Battery recycling ..................................................................................................38
Organizational process and institutional capacity ........................................................39
5.5.1
Training for DRD ..................................................................................................39
5.5.2
Develop training and certification for installers of solar home systems .................40
5.5.3
Library of best-practice SHS videos .....................................................................41
5.5.4
Training booklet & videos for village SHS users ...................................................41
5.5.5
Public exposure to quality products......................................................................42
5.5.6
Burmese smartphone SHS product review app ....................................................42
Appendix A: Survey form for DRD offices..................................................................................43
Appendix B: Survey form for village household surveys ............................................................44
ii
Appendix C: Survey form for SHS businesses -- Supply Sector Characterization and
Assessment ..............................................................................................................................49
Appendix D: Review of DRD SHS specifications .......................................................................50
1
Background ....................................................................................................................50
2
Discussion of specifications ............................................................................................51
3
2.1
System design revision............................................................................................51
2.2
Solar panel ..............................................................................................................53
2.3
Battery.....................................................................................................................54
2.4
Controller.................................................................................................................55
2.5
Inverter ....................................................................................................................55
2.6
Cable .......................................................................................................................56
2.7
LED light..................................................................................................................57
2.8
20 watt fluorescent light ...........................................................................................57
2.9
Phone charger .........................................................................................................57
2.10
Installation standards...............................................................................................58
2.11
Overall system warranty ..........................................................................................58
2.12
User’s manual .........................................................................................................58
2.13
Total cost.................................................................................................................58
Candidate revised specification for solar home systems (2014-5) ..................................58
3.1
Preamble .................................................................................................................58
3.2
solar module ............................................................................................................59
3.3
Battery.....................................................................................................................60
3.4
Controller.................................................................................................................60
3.5
Inverter ....................................................................................................................61
3.6
Wiring ......................................................................................................................61
3.7
LED light..................................................................................................................62
3.8
Installation standards...............................................................................................62
3.9
Overall system warranty ..........................................................................................63
3.10
User manual ............................................................................................................63
3.11
Qualified products. ..................................................................................................63
Appendix E: Sample warranty card........................................................................................65
Appendix F: Interim Battery Acceptance Short Test Procedure .............................................67
iii
iv
Abbreviations
AC
ADB
AGM
CEI
DC
DRD
ESE
FY
GIS
IEA
IEC
ICT
IDTR
kV
kW
kWh
LED
LVD
MoEP
MoLFRD
MSC
MW
NEP
PEA
PO
PPA
REA
REAM
SHS
SPP
SPPA
VRLA
VSPP
Wp
alternating current
Asian Development Bank
absorbed glass matt (lead acid battery)
Columbia Earth Institute
direct current
Department of Rural Development (in MoLFRD)
Electricity Supply Enterprise
fiscal year
geographic information system
International Energy Agency
International Electrotechnical Commission
information communication technologies
Decentralized Infrastructure for Rural Transformation (Bolivia)
kilovolt
kilowatt
kilowatt hour
light emitting diode
low voltage disconnect
Ministry of Electric Power
Ministry of Livestock Fisheries and Rural Development
Medium Term Service Contract
megawatt
National Electrification Plan
Provincial Electricity Authority (Thailand)
Partner Organization (in IDCOL program)
power-purchase agreement
Rural Energy Agency
Renewable Energy Assocation of Myanmar
solar home system
small power producer
standardized power purchase agreement
valve regulated lead acid
very small power producer
watt peak
v
1 Overview
This study investigates the status of solar home systems (SHS) deployed by the Department of
Rural Development (DRD) in the Ministry of Livestock, Fisheries and Rural Development
(MoFLRD). It seeks to understand how SHS that have already been installed are functioning in
the field and to identify design, installation, and usage issues that contribute to failures in the
field. The study discusses the process by which SHS come to be installed in particular
households in particular villages, including how selections are made at the household, village,
and township level; how companies are chosen, how systems are installed, and how
maintenance and warranty service are administered. In addition, the study looks at several
areas not directly related to DRD SHS, but relevant to solar electricity’s role in rural
electrification including DRD solar mini-grids, hire-purchase SHS, solar electric equipment
widely available in rural market towns, and -- through discussions with cell phone companies
and the companies that provide tower services -- the intersection between Information
Communication Technologies (ICT) and solar electricity.
DRD’s SHS program has accomplished important successes, including providing solar home
systems to tens of thousands of households in hundreds of villages. As long as they remain
functional, these SHSs strongly reduce household expenditure for candles, kerosene, and
diesel fuel. This study found monthly household non-heating expenditures reduced an average
of about 12,000 kyat in the villages surveyed. The existence of DRD staff at the township level
provides a good basis for addressing occasional repairs of system components, especially in
villages where the township level DRD staff is in frequent contact with the local village leader.
Despite impressive efforts, the DRD solar home system program is stretched thin in many
dimensions. At the village level, only a portion of households receive systems in villages
selected to participate in the program. With a very low price cap of 200,000 kyat per installed
system, the quality of components and installation is strongly compromised, and companies
struggle to cover costs, especially those companies that take efforts to build systems with higher
than average quality. Warranty and follow-up service are also stretched thin – many villagers
are unaware of their options when equipment breaks and companies have considerable
logistical problems in addressing warranty claims. Program administration is stretched thin with
DRD staff at all levels lacking training in electricity in general and solar home systems
specifically and with the DRD occupied by many other pressing rural development tasks. Based
on sightings of many non-DRD SHS on homes along the routes traveled in this study, SHS
appear very common in rural areas. Solar panels, batteries, Light Emitting Diode (LED) lights
and 12-volt TVs, inverters, and charge controllers are readily available in most market towns.
Much of the equipment is inexpensive and of low quality imported from China or India, and
shops provide little or no guidance in system design or installation.
1
The study concludes with a number of recommendations. There are many opportunities for the
World Bank and other development partners to work with the DRD to improve the situation,
bringing substantial benefits at low cost. Options include: changes in the design of the DRD
subsidy program, targeted trainings and education materials for SHS users, installers,
designers, and DRD; trade finance for SHS companies, revision of DRD specifications, and
product quality assurance through component testing.
2 Background
2.1 Rural electrification and the DRD
At present, about 33 percent of the population in Myanmar has access to electricity from the
national grid. The Government is committed to achieve 100 percent electrification by 2030,
which will require a roughly tripling the current pace of approximately 190,000 new connections
per year.
Myanmar’s National Electrification Plan (NEP), based on analysis by the Columbia Earth
Institute (CEI) projects that ultimately well over 90% of areas will be electrified by the grid. But
many areas may not receive electricity for at least 10 years, even if Myanmar is able to achieve
its ambitious rural electrification grid extension scale-up targets. This leaves considerable scope
for off-grid pre-electrification solutions such as solar home systems and micro-hydropower to
provide basic electricity services (lighting, cell phone charging, TV and DVD players) until the
grid arrives.
The DRD has been given the responsibility of rural electrification. According to DRD Deputy
Chief Engineer U Khant Zaw, off-grid areas are exclusively the responsibility of the DRD, while
on-grid areas are electrified in coordination with the Ministry of Electric Power and especially the
Electricity Supply Enterprise (ESE). Rural areas, for electrification purposes, are defined as
'village tracts' and are the smallest administrative unit in Myanmar. DRD is responsible for
electrification of village tracts, whereas the Ministry of Electric Power (MoEP) is responsible for
rural electrification that involves large communities ("Ward" or "Quarter").
2.2 DRD’s solar home system program
As a key component of its off-grid rural electrification efforts, the DRD is engaged in an
ambitious solar home system program. In FY 2013-14 the DRD oversaw a 4 billion kyat
government budget to procure solar home systems in approximately 300 villages. According to
DRD data, as of April 2014, DRD solar home systems had already been installed in 174
villages. At the same time, 249 villages were newly connected to national grid, or about 0.4% of
the remaining unelectrified villages. In Fiscal Year 2014-15 the DRD is gearing up to install
solar home systems in 170,248 new households in 1491 villages, as well as implement 129
micro-hydropower projects and 8 biomass projects (see Figure 1 below). The total budget is
expected to exceed 37 billion kyat. DRD solar home systems are granted to recipients with
100% subsidy.
2
Figure 1: solar home systems planned by DRD using government budget in Fiscal Year 2014-15. Source: MoLFRD1
The solar home systems are standardized, and include 80 watt solar panel, lead-acid 12-volt
battery, charge controller, inverter, and three lights. This size system is sufficient for cell phone
charging, radio, and – in sunny periods – a two or more hours of operation of a small TV and
DVD player.
This is an ambitious program when one considers that the DRD is a relative newcomer to the
field of rural electrification with staff stretched thin that must cover wide rural territory, generally
in areas with poor roads and communication infrastructure. In some of these areas, logistics are
complicated by security concerns from armed conflict, poppy cultivation, or meth-amphetamine
production. DRD is hampered at all levels by a lack of staff, particularly electrical engineers with
experience in solar electricity.
In the long run, the success of these government-granted solar home systems, and indeed,
rural use of solar electricity in general, will hinge, among other factors, on the quality of the
components and their installation, and whether or not an effective mechanism to provide
maintenance can be implemented. A similar 100% subsidized program implemented in Thailand
1
DRD, “The Implementation of Rural Electrification with Union Budget (DRD) in 2014-2015 Fiscal Year.”
3
of over 200,000 solar home systems in 2004-5 led to widespread failures because inadequate
provision of maintenance.2
2.3 DRD’s solar home system specifications
Companies that participate in DRD SHS tenders are expected to install systems that comply
with the specifications shown below in Box 1.
Box 1: DRD SHS specifications
Specification for Solar Household System(2014-2015)
1။
LED 3 Watt (2)No၊
20 Watt Lamp (1) No Household System
Limited Warranty
(1)
80-90 Watt Solar Pannel
- (1) No၊
(5-10)Years
(2)
Battery 12 Volt (65) Ah
- (1) N0၊
(1-2)Years
(3)
Controller (10)Ah(12V-24V)
- (1) No၊
(5-5)Years
(4)
Inverter 300 Watt
- (1) No၊
(5-5)Years
(5)
Cable (5)Meter
- (3) No
(6)
LED 3 Watt
- (2) No
(7)
20 Watt Lamp
- (1) No
(When -TV-21''Flat LCD is ON 20Watt Lamp has to be OFF)
( 8) Phone Charger
- (1) No
( 9) Total Cost
- (200000) Kyats
The specifications do not include equipment quality or installation quality standards. Appendix D
provides a detailed review of these specifications and offers a suggested improved set of
specifications, briefly summarized below in Table 6 on page 35.
3 Scope and Methodology
Field work for this study included site visits between 29 November and 12 December to 10
villages with DRD SHS systems, two unelectrified communities without DRD systems, and 6
DRD offices in Kayin State, Thanintharyi District, and Shan State, as well as interviews with
SHS installation companies and ICT companies in Yangon. Visits to DRD offices and villages
were completed with the assistance of professional translator Sai Nay Lin as well as a
representative of the DRD Naypyitaw office, Zin Lin Htun.
Andrew Lynch et al., Threatened Sustainability: The Uncertain Future of Thailand’s Solar Home
Systems., June 2006, http://www.palangthai.org/docs/SHSReport6June06.doc.
2
4
DRD offices. The team visited and surveyed DRD offices at the state, district, and township
level. In interviews with these officials the team sought to understand how many DRD SHS have
been deployed in their area in the past fiscal years, the DRD office’s level of experience and
interest in training, the procurement process including vendor selection, and how villages are
selected. The survey form used for these semi-structured interviews is included in Appendix A.
Village visits. 10 villages to visit were selected by the DRD, comprising two villages in Kayin
State, five in Thanintharyi State, and three in Shan State. In each village visit the author was
accompanied with two or more DRD local officers, usually one from the state or district level and
one from the township level. Villages visited in the course of this study comprised 1288
households and accounted for 597 solar home systems installed in homes, with another 27
installed in schools or other public buildings. The villages, locations, and quantity of households
and SHS installed are described below in Table 1.
Table 1: Villages surveyed in SHS assessment and associated SHS installation data. Coordinates in italics are
approximate.
Date
visite
d
(2014)
1-Dec
Village
name
District &
State
Latitude &
Longitude
Date
SHS
installed
Company
Total
households
in village
Yay Kyaw
Gyee
Hpa An,
Kayin
N
16.87110,
E 97.65658
Mar-13
1-Dec
Pan Gong
Pan Taw
N 16.73273
E 97.58802
N 14.07641
E 98.19622
Jun-13
3-Dec
Hpa An,
Kayin
Dawei,
Thanintaryi
Industrial
Department
before
program
moved to DRD
Moe Ko San
3-Dec
Thar Byar
Dawei,
Thanintaryi
N 14.07260
E 98.26978
Nov-14
3-Dec
Taung Poh
Dawei,
Thanintaryi
N 14.06982
E 98.25923
Nov-14
6-Dec
Taung Pa
Le
Ma Zaw
Pyin Gyee
Myeik,
Thanintaryi
Myeik,
Thanintaryi
Apr-12
9-Dec
Pan Lian
Loilem Dist,
Shan
9-Dec
Thien
Phan
(Lahu)
Khaung
Nwe
Loilem,
Shan
N 14.14239
N 98.09141
N12.36776
9
E98.83527
3
N21.28789
1
E98.53136
7
N21.27524
E98.48477
Loilem,
Shan
N20.87991
E97.49532
6-Dec
10Dec
370
Total
households
receiving
SHS
90
Schools,
etc.
receiving
SHS
14
110
110
4
Aung
Myanmar
Coop
Earth
Renewable
Energy
Company
Earth
Renewable
Energy
Company
SolaRiseSys
102
102
160
34
122
26
140
94
Mar-14
Ant Htoo
Gabas
90
32
Apr-14
Myanmar
Solar Power
18
18
Apr-14
Myanmar
Solar Power
56
18
Dec-13
Zabuyit Pale
Co. Ltd.
120
55
Jan-14
5
10
Total
1288
597
27
In each village, the team surveyed two or more households selected at random collecting usage
data, socio-economic information, energy expenditure data, and performing a technical
assessment of the current status of the system. The 115-question survey form used to guide
these semi-structured interviews and equipment inspections is included in Appendix B.
In the technical assessment portion of the SHS inspections, data collected included solar panel
short-circuit current and open-circuit voltage, solar insolation, solar panel orientation and tilt,
battery voltage while resting and under charge, electricity consumption of lights, inspection of
wiring, and dimensions and quality of wiring.
Solar home system companies. The team conducted interviews with manufacturers, system
integrators, and installers in Hpa An (1 company) and Yangon (5 companies) to determine
products and services offered, pricing, equipment sourcing, staffing levels and experience, solar
experience, company practice and policy regarding warranty provision, and major issues in the
industry. Of these six companies, three installed SHS that were encountered in the village visits.
Survey forms for semi-structured interviews is included in Appendix C.
ICT companies. The team conducted in interviews with one cell phone service provider and two
tower companies to explore the intersections between ICT and rural electrification, including
incorporating mobile money technology into pre-pay meters, use of cell-phone data carriers to
provide real-time monitoring of remote mini-grids, and interest of parties in business models that
include provision of electricity to both cell-phone towers while also electrifying a surrounding
village.
4 Research results
The following sections describe the results of the fieldwork. These start with a discussion of the
village selection process and tendering processes used by DRD. This is followed by village
findings based on interviews of users and technical assessments of a number of SHS
performance parameters. The section ends with a discussion of mini-grids and non-DRD
systems encountered in the course of the fieldwork.
4.1 Village selection process
With tens of thousands of villages to choose from, the DRD has a significant administrative task
in choosing priority villages to receive SHS and to determine how many SHS to allocate to each
village. Based on discussions with DRD staff at the state, district and township levels, this
process is initiated from the bottom-up, starting with the township level. The process comprises
the following steps:
1. At the township level, a group comprising the village leader representatives to the
township, the DRD officer for that particular township, and a committee of other
6
2.
3.
4.
5.
6.
7.
8.
9.
important local figures draws up a list of villages suitable for receiving SHS. The
committee also divides the list roughly in thirds, assigning each village to the category
1st, 2nd, or 3rd priority. This determination takes into account:
a. Distance from the main grid (or, where there is no main grid, distance from the
nearest town);
b. Village income (poorer villages get priority);
c. Existence of privately-purchased SHS or diesel generators (those without SHS
are prioritized); and
d. Villages' other priority infrastructure needs (e.g. water, road -- if water is a
priority, DRD will focus on that instead) and an attempt to balance who gets what
(e.g. if one village gets SHS, another might get a road).
After the meeting, the DRD township official takes this list to the DRD district office,
where modifications are made if the district office sees fit.
The list is then presented to the regional DRD which may make modifications as well.
The regional office then sends the list to the Naypwitaw office of the DRD which adds it
to those from other regions and adjusts the lists if appropriate. Here Naypwitaw DRD
Director U Khant Zaw plays a key role, together with the Minister of MoLFRD.
The list goes to the MoLFRD where an overall budget is proposed.
The budget (or a modified version) is approved by Parliament.
Funds are then sent back to the state/regional DRD office, which adjusts the list and
SHS per village in accordance with the actual budget allocated.
The district office then initiates the tender process (described in 4.2 below), and awards
contracts based on price, quality and "guanxi"3. If the winning bid price is lower than the
200,000 kyat cap, the DRD office generates a proposed use of the savings (e.g. building
a road to a specific village) and informs the head office (NPT) to seek agreement.
It is the village's responsibility to determine how SHS are distributed if, as often is the
case, there are not enough for one for every household. The process that villages use to
allocate SHS is discussed in 4.3.1 below.
Figure 2: DRD SHS Village selection process
3
In Mandarin Chinese, guanxi refers to the system of social networks and influential relationships that
facilitate business and other dealings.
7
4.2 Tendering process
Once the village selection process is complete, the tendering process may proceed. SHS
tendering is done at the same time that other DRD infrastructure (road, bridges, water, house
construction, latrines) are tendered out. The tendering process appears to vary somewhat from
region to region. In Thanintharyi, tendering is conducted at the regional level. In Shan and Kayin
state, a committee that oversees tendering is convened at the state level. In Shan State the
state government minister is chair, and the State DRD director is secretary. Five other state
level members on the committee include: (1) General Administration Department; (2) Public
Works Department; (3) Irrigation Department; (4) State Development Committee; and (5)
Planning Department.
The tendering committee places advertising in local newspapers, TV, and radio indicating the
day that the tender documents are available. In response, bidders come to the DRD office and
collect bid documents, fill them out, and return with a sample SHS to demonstrate. This FY
(2014-5) 48 companies applied for the SHS program in Shan State, of which 44 won contracts.
Of the 44, four are from Shan State and the rest mostly from Yangon. In Kayin state, five
companies won SHS tenders. As part of the decision in awarding tenders, the state committee
determines how many systems are allocated to what companies in what villages. The final list is
then returned to the DRD. Some companies get 2-3 townships. In other cases -- with bigger
townships, one township may serve 2-3 companies. The price they receive is independent of
how remote the village is.
Once installation is complete, a township DRD officer visits to ensure the systems were actually
installed, and then the township office transfers payment to the company. The township officer
has responsibility for regular follow up, but this is difficult because of limited staff. In theory the
township officer visits at least two times per year and calls the company if there is a problem
with broken equipment.
8
DRD staff at all levels (union, state, district, township) expressed that that they have little
experience and ability to make good judgments about selecting vendors. All they have to go on
is the demonstration unit that a vendor sets up in front of the panel. The DRD only has the skills
to check the components against the DRD specifications, but have limited ability to judge quality
of the design and components.
4.3 Findings from village visits
Through interviews with villagers and inspections of SHS in operation in people’s homes, the
team gathered information on how SHS are allocated within the village; the socio-economic
profile of village homes with SHS; the benefits from SHS – particularly in the form of reduced
expenditures for kerosene, diesel, and candles; usage patterns, and how villagers address
problems that arise when SHS equipment breaks. Inspections of SHS covered a wide range of
parameters covering wiring, solar panel, charge controller, battery, inverter, lighting, and the
operations manual.
4.3.1 Allocation of solar home systems within village
In three of the ten villages, enough solar home systems were provided through the DRD
program to install one in every house. In the remaining seven villages, a fraction of the
households -- between 21% and 67% -- received SHS. In the villages visited, on average 45%
received SHS.
In all villages visited the decision of how to allocate SHS among households was left to the
villages to decide. In five of the villages, SHS were allocated on a simple lottery basis. Khaung
Nwe village employed a slight variation: the village of 120 households was allocated 65 SHS
and the village decided to allocate one each to the clinic, school, and monastery. Another seven
SHS were provided to poorer households. The remaining 55 distributed by a lottery system.
Taung Pe Le village has 140 households, but only 94 SHS were available. The village set up a
first-come-first-served process in which those who wanted SHS paid 30,000 kyat. The payments
were pooled to purchase (smaller) SHS for those that did not receive them from DRD.
4.3.2 Customer profile
Of village households with DRD SHS that were interviewed, the strong majority were farmers
(94%) mostly growing paddy and vegetables, while a few operated small shops (23%).4 One
respondent was a seasonal laborer and wood cutter. Another ran motorcycle repair business
and sold fuel. Two provided transportation, either in the form of a motorcycle taxi, or a larger
tractor/wagon for group trips to the nearby town.
Reported monthly income ranged from 0 to 500,000 kyat per month, with an average of 115,000
kyat per month. Household size ranged from 2 to 7 members, with an average family size of 4.2.
In 35.3% of households SHS were operated by both men and women, 35.3% by women only,
4
Sum exceeding 100% indicates multiple occupations.
9
and 29.4% by men only. Homes were generally wood with tile or metal roofs (58%), while the
remaining significant minority (42%) had grass or bamboo roofs and homes with bamboo floors.
4.3.3 Savings enabled by SHS
As long as SHS remain functional, the benefits of SHS to household cash flow are stark. Prior to
installation of the SHS, villagers in 20 households queried paid between 2600 and 50,000 kyat
per month on non-heat energy, with an average expenditure of 13,400 kyat/month. This money
was spent on candles (about 100 kyat per night), kerosene lamp oil (a 0.66 liter bottle costs
about 700 kyat and lasts 2-3 days) and, in some cases, diesel fuel for a household generator or
shared community diesel generator.
After the installation of the SHS, most households’ routine non-fuel energy expenses reduced to
zero5. When asked about how life has changed with the SHS, most respondents mentioned the
reduction expenditures for energy. A distribution of household expenditures before and after the
SHS is shown below in Figure 3, sorted from highest to lowest. In the figure, household #1
(which had been paying 50,000 kyat/month, the highest) reduced to 15,000 kyat/month but
continued to operate a diesel generator for TV. Households #11 and #19 had broken SHS and
now pay the same that was paid prior to the SHS, demonstrating the obvious but important fact
that SHS save money only when they are working. Household #12 pays the same as before
because it is a customer of a community diesel power mini-grid with a minimum monthly
payment of 7000 kyat/month for up to 10 kWh per month. At the end of the month the
homeowner uses any remaining quota to iron clothes. The SHS in this particular case was
installed only a week prior to the visit, so the household may yet decide to not renew the diesel
generator membership.
5 Six
households reported they still bought candles for use in their family altar, paying about 100 kyat per
night (3000 kyat/month). This is arguably a religious expense and not an energy expense since solar LED
lights could be used (and many households do use) in the altar.
10
Figure 3: Distribution of household expenses before and after SHS for non-heat energy in Myanmar Kyat per month.
Most households pay zero non-heat energy expenses after installation of the SHS.
60000
50000
KYAT PER MONTH
40000
30000
20000
10000
0
1
2
3
4
5
6
7
8
9
Before SHS
10
11
12
13
14
15
16
17
18
19
20
After SHS
4.3.4 Usage patterns
Electricity from solar home systems is predominantly used for three purposes: lighting, TV/DVD,
and cell-phone charging. DRD SHS recipients each received three LED lights. Indoor lights are
powered between 3 and 10 hours per night, with an average of 4.9 hours per night. Three out of
24 households had installed one of their lights as an outdoor light and typically that light was
powered “all night” – about 10 hours per night.
TVs (or “laptop” DVD players) were used in 47% of households surveyed. While these were
mostly powered through the inverter, four households use 12-volt DC TVs. TV watching in some
cases is seasonal. For example, one house in Myeik, Thanintharyi reported that they could
watch two hours of TV per night except during the rainy season. During the rainy season TV
was switched off in order to ensure sufficient electricity for lights.
Like TVs, cell phone charging can be done either with DC or AC. Many cell phones charge
using a standard USB (5 volt) connector. Even though not required by the DRD specifications,
five companies (Earth Renewable Energy Company, Moe Ko San, Ant Htoo, Myanmar Solar
Power, and Zabuyit Pale Co.) supplied USB charging ports in addition to 12-volt lighting
receptacles and 230 volt outlets. Sixty nine percent of DRD SHS encountered were used to
charge cell phones, either using the inverter or a USB port. Charging with an inverter is not
11
recommended because if the inverter is turned on only to power the cell phone the inverter is
operated at a point on its power curve where it is less efficient.
4.3.5 What happens when something breaks
The DRD specifications indicate warranties for key components (5 years for PV panel, controller
and inverter, 1-2 years for battery as indicated in Box 1). In the village, however, knowledge of
the warranty, or how to go about making a claim was sparse. No one in the village specifically
knew that there is a warranty.
Follow-up varied from excellent to non-existent. On the one hand, a resident of Pan Taw Village
(installed by Aung Myanmar Coop) reported that the DRD comes to check about 6 times per
year, and the company came three times per year and changed out broken LED light bulbs.
Much more common was lack of follow-up and lack of information about whom to contact in the
event of a problem. When asked what people do when something breaks, more than 60%
replied either “I don’t know” or “we try to fix it ourselves”. Twenty percent of respondents contact
the village leader who aggregates reports of broken equipment and contacts the installation
company. None of the companies based in Yangon who installed systems in the villages visited
maintain permanent staff in the state or district. Considering that all actually do perform
installations, it follows that these companies have access to technicians (generally based in
Yangon) with the skills to perform equipment replacements.
4.3.6 Technical assessment of DRD SHS performance and equipment quality
The following subsections detail the technical performance of DRD SHSs encountered in the
field, including wiring, solar panel, charge controller, battery, inverter, lighting, and the presence
or absence of a user manual. Overall, 16 out of 23 systems inspected (69.6%) were functioning
properly.
4.3.6.1
Wiring
4.3.6.1.1 Wiring installation
In all houses visited except one, wires (especially wires to lights) were draped on rafters and
nails, creating hazards and opportunities for wires to be pulled and broken in the course of dayto-day activities in the house. The one house visited with correctly installed wiring was rewired
by the household residents after the installation team left.
12
Figure 4: examples of sloppy and hazardous household wiring. In bottom photo notice location of nail immediately
next to DC inverter terminals creating a significant fire hazard as these unfused wires are connected directly to the
battery terminals.
4.3.6.1.2 Splices and connections
In at least 90% of the SHS installations visited, wires (especially the wire from solar panel to
controller) were improperly spliced. Generally wires were simply stripped, twisted and taped, or
using an interior-rated terminal connector. Neither of these splice methods provide protection
against corrosion from rain and moisture. Splices of this nature will fail when water intrudes and
corrodes contacts.
13
Battery connections are particularly important because current passes twice (on charge and
discharge) through these connections, and because battery terminal connections are
particularly prone to corrosion resulting from mismatch of alloys between battery cables and
terminals.
Figure 5: Example of poor splice with wires simply wrapped and taped, also positioned so that it will be soaked in the
rainy season.
4.3.6.1.3 UV resistance of exterior wires
The PV-to-controller circuit in over 90% of installations surveyed used interior-rated wires that
lack UV-light resistant insulation. In a few years, UV light will make the insulation brittle, creating
possibilities of short circuits and setting conditions for the wire to corrode.
4.3.6.2
Solar Panel
4.3.6.2.1 Solar panel certification and quality standards
In DRD SHS encountered in the field visits, solar panels without brands were used by 3 out of
10 companies (Industrial Department, SolaRiseSys, Ant Htoo Gabas). 5 out of 9 companies
used solar panels with IEC certification (SolaRiseSys and Earth Renewable Energy Company).
In addition, one company interviewed in Yangon (but whose systems the team did not see in the
field) used certified PV modules (T & T Ltd.). One company used solar panels with solar cells
that were visibly chipped and discolored (Myanmar Solar Power).
14
4.3.6.2.2 Solar panel performance
As an indicator6 for solar panel performance, temperature-adjusted7 and insolation-adjusted
rated short-circuit current is compared against the solar panel’s measured short circuit current.8
Ratio of measured Isc to adjusted-rated Isc =
(I𝑠𝑐−𝑟𝑎𝑡𝑒𝑑 )(
I𝑠𝑐−𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑑
Insolation
𝑊 )(1+(T−25))(𝐼𝑠𝑐𝑡𝑒𝑚𝑝𝑐𝑜𝑒𝑓𝑓𝑖𝑒𝑛𝑡 )
1000 2
𝑚
Where:
Isc-measured is the measured short-circuit current (in Amperes),
Isc-rated is the rated short-circuit current (in Amperes),
Insolation is the measured global solar insolation in the plane of the array (in watts/m2),
T is the measured ambient temperature at the solar panel in degrees Celsius,
Isctempcoefficient is the typical temperature coefficient for short-circuit current for crystalline
silicon solar cells (0.061 %/deg C).
Only one solar panel produced a short-circuit current within 90% of its adjusted rated short
circuit current. Most (9 out of 11 measured) performed below 50%. Three of the solar panels
with IEC certification had the highest scores (Figure 6 below).
Caveats should be noted: the insolation measurement and the short circuit current
measurements were not taken at the same instant. Variations in cloud cover in the interval
between measurements are a source of possible error (though mostly skies were clear). Also,
low short-circuit current readings are attributable in part to dust on the module surface reducing
the amount of sunlight reaching the cells rather than entirely due to below-spec performance.
Low readings are not attributable to shading, as insolation measurements were taken in the
plane of the module, and thus subject to any shading that the module was subject to. This
method of assessing PV performance is indicative only and does not take into account the solar
panel’s voltage performance or its fill factor (the ratio of maximum power production divided by
the product of Voc and Isc) – factors likely to work even further against the chance of the module
meeting specification.
The persistently low indicator of performance measurements suggest that many solar panels
installed in DRD SHS perform substantially below their rated output.
Figure 6: PV performance indicator defined as the measured short circuit current divided by temperature- and
insolation-adjusted rated short circuit current. A value of “1” indicates the PV module is performing consistent with
6 Fully
testing each module would have required a laboratory with a IV-curve tracer and a calibrated light
source.
7 Typical temperature coefficient for short-circuit current is 0.061 %/deg C. Source: http://forum.solarelectric.com/showthread.php?15312-Temperature-Coefficients.
8 Short-circuit current and temperature were both measured with a factory Fluke 197 True RMS
Multimeter (factory calibrated 11/11/24). Solar insolation was measured with a Dr.Meter SM206 Digital
Solar BTU Power Meter.
15
rated capacity. Only solar panel #1 (SHS in Khaung Nwe village installed by Zabuyit Pale Co. Ltd.) had a measured
performance indicator exceeding 90%. Data label indicates whether the panel had IEC certification.
1
IEC
0.9
0.8
0.7
IEC
0.6
IEC
0.5
0.4
IEC
0.3
0.2
IEC
0.1
0
1
2
3
4
5
6
7
8
9
10
4.3.6.2.3 Solar panel orientation
Most SHS systems encountered had the solar panel installed with large (and sometimes very
large) deviation from orientation towards true south9, as shown in the “error” column in Table 2
below.
Table 2: solar panel orientation and error from true south
Orientation (180 = true south)
46
222
175
197
182
193
150
93
302
205
267
229
201
Error (Degrees from true south)
134
42
5
17
2
13
30
87
122
25
87
49
21
9
Orientation measurements were made with a Garmin GPS which is not affected by magnetic
declination.
16
4.3.6.2.4 Shading
Many solar panels were significantly shaded at the time the system was inspected or were
installed in locations that would clearly be shaded for significant portions of the day. In large part
this is a consequence of PV-to-controller wire lengths that were too short. The DRD
specifications indicate wires shall have a length of 5 meters, which in many cases is inadequate
to reach sunny areas. In other cases, shading is simply the result of not paying sufficient
attention to unshaded south-facing options.
4.3.6.2.5 Solar mounting
Companies varied considerably in the quality of the solar mounts that were used. On the high
quality end, Earth Renewable Energy Company used substantial wooden poles with engineered
steel brackets. On the low-quality side, SolaRiseSys used poles of small diameter
(approximately 3 inch) and of soft (rot-prone) wood which appear likely to fail by the end of the
next rainy season. These should be replaced soon with more substantial, rot-resistant materials.
Many households, especially those that installed their own SHS, simply laid the solar panel on
the roof (generally corrugated iron). This presents dual problems of (a) overheating because
insufficient air gap is provided between the hot roof and the panel’s back surface; and (b) high
risk of the solar panel blowing off the roof and falling to the ground in high winds.
Figure 7: Rot-prone, small diameter poles, flimsy mounting
4.3.6.3 Charge Controller
All SHS were originally installed with charge controllers, but these vary considerably in quality,
functions, and durability. In a number of cases these were bypassed.
17
4.3.6.3.1 Controller circuitry type
Controller circuitry varied considerably in terms of function and durability. On the worst end of
the scale, the SHS systems installed under the Myanmar Industrial Department (prior to the
DRD) contained a very simple relay-based controller with no indicator lights of any kind. At least
half of these controllers had failed after 21 months of use.
All of the SHS installed under current DRD program were installed with solid-state switching,
which is considerably more reliable than relay type controllers. At least one controller type
encountered in the field (Earth Renewable Energy Company) uses pulse width modulation
(PWM) – a feature that helps prolong battery life by tapering current as the battery approaches
full state of charge, rather than simply turning off current when the battery reaches a certain
voltage.
4.3.6.3.2 Low Voltage Disconnect (LVD)
In the case of “plug and play” systems it was impossible to determine which had Low Voltage
Disconnects (LVDs). Visual inspection of the circuits suggested that LVDs were included.
Systems with discrete components (as opposed to components installed in a single metal box)
all had controllers with LVDs except one (Myanmar Industrial Department (installed prior to the
DRD SHS program). In all cases, inverters were not wired through the LVD terminals, allowing
inverter-based appliances to deplete battery charge down to the level at which the inverter turns
off or sounds a low voltage alarm. This is not necessarily an error, as LVDs are generally
current limited (typically 10 Amperes) -- effectively reducing the maximum power output from the
inverter from 300 watts to 120 watts (12 volts x 10 amperes). However, it does create additional
risks that inverter-powered appliances will draw down the battery below a safe voltage.
4.3.6.3.3 Fused vs. electronic-based current limiting vs. no protection
Controllers generally have over-current protection and protection against reverse polarity. Those
that use fuses to provide this protection are more likely to fail or be bypassed compared to
controllers that use electronic means of overcurrent protection. In the case of controllers with
fuse protection, the typical progression of events leading to failure is that a short circuit or
reverse polarity incident melts the fuse, rendering the controller inoperable. If a spare fuse is not
available the user simply bypasses the controller or “fixes” the fuse by covering it with aluminum
foil. The next time a short occurs, the meter’s (now unprotected) circuitry is damaged. Of solar
home systems installed by nine companies that the team observed in the field, four companies
used fuses to provide overcurrent and reverse polarity protection. Fuses had blown in two of the
systems installed by these companies. Of the remaining five companies, it was impossible to
determine without either seeing the specification sheets or potentially destructive component
testing whether the controllers had electronic current limiting or had no protection.
4.3.6.3.4 Controller bypassed
Out of 24 systems visited in the field, the charge controller was bypassed in two systems,
leading in both cases to severe overcharging of the battery and depletion of battery electrolyte
to such an extent that the cell plates were exposed to air. Controllers in systems in which
18
components were assembled together in a single “plug and play” box were less likely to be
tampered with and bypassed compared to those using discrete components.
4.3.6.4
Battery
4.3.6.4.1 Battery types
All companies with systems encountered in the field used sealed lead-acid batteries except one
company (Aung Myanmar Coop) which used a flooded lead-acid type battery. Sealed
“maintenance free” batteries require less maintenance (especially topping up cells with distilled
water), but flooded batteries can last longer if properly maintained because they accommodate
equalization charges (periodic intentional overcharging to remove sulfation). Flooded batteries
require additional installation steps as well: they are generally shipped dry, and electrolyte must
be added and an initial forming charge performed before use.
Among sealed lead acid batteries manufactured worldwide, the most common are Absorbed
Glass Matt (AGM) batteries – also known as valve regulated lead acid (VRLA) batteries. AGM
batteries were also probably the most common sealed battery encountered in the field, but most
batteries lacked sufficient marking to make this determination.
4.3.6.4.2 Battery enclosure
Batteries in systems installed by two companies (Zabuyit Pale Co. Ltd. and Myanmar Solar
Power) included metal box enclosures – as required by Shan State DRD specifications.
Batteries installed by all other companies either had no enclosure. Battery enclosures improve
safety by reducing the chance of accidental short circuits by dropping a metal device across the
terminals and protecting small children from direct encounters with the battery. Enclosures may
also reduce tampering.
The metal enclosure in Shan state is required to prevent, of all things, the use of batteries for
shocking fish. When 44 companies submitted example systems in the Shan State tendering
process, some had all the components in a single metal cabinet box, others had separate
components. After seeing the systems in a single box, the tendering committee reflected on
their experience that if the system has separate components, many villages will take the battery
down to the local fishing hole and use it to shock fish. Out of concern for the battery (and
perhaps the fish) the committee felt that it was important to put the battery in a metal box with
everything else since they felt this would help deter villagers from this misuse of the battery. The
committee informed the bidders that their winning bids would only be accepted if they put all the
components in a metal box. At least one company complained, saying, "the box alone costs me
20,000 kyat" but none of the companies pulled out.
4.3.6.4.3 Battery failures
Out of 26 SHS investigated, batteries had clearly failed in three installations and a fourth was
very weak (with voltage dropping immediately from 12.9 volts to 11.3 volts when PV was
19
removed). Others may have been close to failure, but because visits to villages were during the
daytime, higher voltages from recent solar charging almost certainly masked some battery
problems. 10
Table 3: Battery failures observed in DRD SHS
Company
Myanmar Industrial
Department
SolaRiseSys
Zabuyit Pale Co.
Ltd. Taunggyi
Battery type
Sealed
Battery age when visited
less than 20 months
Flooded
(replacement
for earlier
battery)
Sealed
7
Comments
Probably caused by controller failure. 20”
LED TV and DVD players were loads.
Probably caused by controller failure
Battery apparently damaged – acid
reportedly leaked out at time of installation
but the recipient did not bring the issue to
the attention of the installer.
13
The range of battery ages encountered was zero to 24 months, with an average of just over 12
months. Under the conditions and considering the common lifetime of batteries, DRD should
expect high failure rates in coming months.
Figure 8: (Left) Voltage of this (dead) battery is 8 volts starting the evening. (Right) closeup of overcharged battery
cell with lead plates exposed (non-DRD system with no charge controller).
10
An observable characteristic of a failing battery is that its voltage rises quickly under charge and falls
relatively quickly when discharging (e.g. 1 hour at a C/10 discharge rate depleted to a low voltage cutoff
of 11.5 volts instead of 10 hours with a healthy battery). Stated simply, its capacity appears diminished.
During the daytime – when the battery is charging, and with access typical loads in a village household, ,
this depletion still takes too long to observe in the course of a typical household visit. A charged but
battery failing battery will still appear to hold charge when measured in the short run running relatively
small loads. As a lesson learned, future SHS inspections would benefit from the use of a dedicated
battery analyzer tool rather than a voltmeter and village loads.
20
4.3.6.4.4 Battery recycling
Questions about battery recycling and disposal of used batteries were not included in the village
survey instrument, and therefore were not part of the average village household interview.
However, in the course of interviews the team did ask several village households what they do
with old batteries. The answer was consistent: people save old lead acid batteries because
every several months a truck arrives traveling from village to village purchasing old batteries by
the kilogram. More research is necessary to determine if the price of lead seems is sufficiently
high (about $1 per pound internationally) that the private sector addresses dead battery
collection effectively, and whether private sector recycling can expand sufficiently fast to match
the growth in SHS under an expanding DRD program.
4.3.6.5
Inverter
4.3.6.5.1 Inverter failures
Overall, inverter failures were noted in 4 out of 23 households surveyed. In Taung Pa Le village,
Myeik, Thanintharyi State (installation by SolaRiseSys in April 2012), about 60 households used
the inverter in their SHS to power a TV. Of these 60 households, the village leader estimated
that 90% (about 54) of the inverters had failed. In Ma Saw Pyin Gyee village in Myeik,
Thanintharyi State (installation of 32 SHS by Anto Htoo Gabas in March 2014), the village
leader estimated that 50% of inverters in the village had failed.
4.3.6.5.2 Inverters and lighting
Fortunately, inverters were used to power lights in systems installed by only three out of twelve
companies: Earth Renewable Energy Company and the “pre-DRD” Ministry of Industry (all three
lights), Mo Ko San (tube light only) and Aung Myanmar Coop (tube light only). Powering lights
21
with inverters lowers resiliency and reliability because if the inverter fails the light cannot be
used.
4.3.6.5.3 Inverter non-use
In Thien Phan village, Loilem District, Shan State no inverters were broken because none were
used. They inverters were still in their original bubblewrap. Villagers reported they could do
everything they needed (lights, cell phone, TV) with DC.
4.3.6.6 Lighting
All companies provide at least three LED lights. One company (Earth Renewable Energy
Company) provided four. The LED lights came in sizes of 3, 5, 9 and 10 watts. Most systems
provided a mix of two smaller (3 to 5 watt LEDs) and one large (9 or 10 watt LED light). One
company (Zabuyit Pale Co.) provided three 9 watt LED lights. Most LEDs were DC, but (as
discussed in the section 4.3.6.5.2 above) several companies provided AC lights powered
through the inverter.
Lighting installed outdoors was, in every case, an indoor rated fixture installed outdoors with
generally inadequate shielding from rain. Of 24 households in 11 villages, LED light failures
occurred in four households. Three of these were in systems installed in April 2012 (older than
most) by SolaRiseSys.
Figure 9: Interior lamp fixtures used in outdoor applications with insufficient rain protection. This
22
4.3.6.7 Operation manual
DRD specifications do not require an owners’ manual, but one is clearly needed. About 45% of
respondents said they had received a ‘manual’ but in all cases this was actually just a single
sheet of paper listing 5-10 rules such as “don’t use a rice cooker” and “don’t make modifications
to the system”. While better than nothing, this does not provide users with the necessary
understanding of their SHS to use and maintain it properly.
Figure 10: “Operations manual” in Yay Kyaw Gyee village, Kayin State consists of a single piece of paper listing
prohibited actions.
4.3.7 DRD centralized systems
While the SHS are the most common form of solar electrification, DRD appears to have
considerable flexibility to accommodate both solar mini-grids and central battery charging
stations where conditions are appropriate.
In Thit Sar Aye Myaing village (N 17.18369; E 97.67213) in Kayin State are nine PV mini-grids
installed under the DRD program in Dec 2013 by Moe Ko San, a social enterprise PV company
in Hpa An. The village was chosen for a mini-grid because it is a fairly dense settlement with
households in a grid pattern. Each of the nine identical systems has the following key
components, all manufactured in Korea:
 3 @ 250 watt, 72-cell solar panels, IEC 61215 certified,
 two 12-volt 250 Ah batteries (in series) lead calcium sealed
 1000 watt, 24-volt inverter
 Controller (20 A)
In each of the 278 houses in the village power is provided two AC LED lights (3W) plus 201 LED
street lights (5 W). In addition, a central station provides cell-phone charging. No outlets are
23
provided in households and TVs, irons, rice cooking, torch charging are prohibited. The system
is only turned on from 4-6 am and from 6-9 pm.
Figure 11: One of nine AC mini-grids installed at Thit Sar Yeik Myaing village in Kayin State.
The system was well-installed but there are some significant problems technical problems and
user problems.
User problem: some users have tried to run TVs by disconnecting the wires to the light and
routing it to a TV. Short circuits created by sloppy handling of this process trips breakers in the
house and sometimes fries transistors in the inverters.
Technical problem: two batteries exploded. Others are starting to fail. Battery voltage under
charge for batteries comprising two separate 24-volt series string were radically different
voltage. In one case, 11.6 and 13.93; another case 11.62 and 14.10. This was under conditions
of about 20 charging amps. Clearly the batteries at 11.6 volts are in trouble. In another case, a
pair of batteries was at 16.52 volts and 15.82 volts respectively. This is far too high for a sealed
12-volt led-acid battery.
The battery problems including exploded batteries almost certainly the result of charge
controllers set with a high voltage disconnect that was far too high. Sealed lead-acid battery are
subject to thermal runaway and voltage must be carefully regulated to prevent overcharge. In
the village many controllers were set to 33.6 volts. Default factory setting is 27.4 and elsewhere
a recommended setting for a 24-volt VLRA battery is 28.2 to 29.4 volts.11
11 http://www.homepower.com/articles/solar-electricity/equipment-products/ask-experts-battery-queries
24
4.3.8 DRD battery charging station
In Thein Phan Village, Loilem District, Shan State, the company Knowledge Nugget provided
portable battery packs that include a 2.8 Ah 12-volt battery, two 3-watt LED lights and two USB
charging plugs. Twenty charge from a single 140 watt module. The woman we interviewed liked
it because it is portable. These are not exactly under the DRD budget; we were told they were
donated, but the DRD looks after them and has provided repairs, especially for cables that were
failing. At least two other companies active in the DRD SHS program – T&T Solar and Asia
Solar -- are producing similar very small portable battery pack charging systems.
4.3.9 Hire purchase SHS
In addition to DRD SHS which are given to villagers for free, at least one “hire purchase”
program operated by a (separate) branch the Myanmar government is in existence.
One system observed that was installed under the program was similar to DRD SHS in Shan
State, but with smaller solar panel and battery.
 Components in a powder coated metal cabinet.
 Battery 12 V 40 Ah valve-regulated lead acid
 40 watt solar panel (mounted on roof). At the time (about 2pm) it was producing:
o Isc = 2.6 amps
o Voc = 20.14 volts
 Inverter rating: 500 watts. No brand. Transformerless type, gold color, with one outlet
which had been removed and AC wires connected to two outlets on the metal chassis.
 Charge controller with LVD. Brand: Sinoware. Like the inverter, it had also been
"hacked" with its LED indicators rewired to light up tiny LEDs on the chassis.
 Five 12-volt receptacles
 Three LED lights each 3 watts.
The program is operated by the Mandalay State Project Planning Department, working together
with a private company, Heatec, which manufacturers the hardware. The government
department purchases the equipment from the company, provides marketing, distributes the
equipment, and collects payments. Reportedly, “thousands” of systems have been installed
under the program. The author encountered a family with one of these systems in Mai Pon
town, an unelectrified area outside of the municipal area of Pwin Oo Lwin, Mandalay. The
system was installed in December 2013.12
The price of the system to users is 450,000 kyat (about $450) paid in a 1-year installment plan
with 9.75% interest. Considering the smaller equipment, and the similar quality of the equipment
and installation, this seems quite expensive compared to the 200,000 Kyat cost of a system with
larger battery and larger PV module under the DRD programs. At the time of the interview, the
family still had three months of remaining payments to make. The bearings of the inverter’s fan
12 Contact
of person at government office: U Sanye Win (09493177), State Department Manager.
25
were failing, making a loud screeching noise whenever it was turned on. The family reported
that it was “difficult to reach the company for repairs.”
4.3.10 Privately purchased SHS
In the course of conducting field visits on DRD SHS, the team inspected eight solar home
systems purchased by users themselves and saw hundreds more from afar. Several
observations are worthy of note: (1) user-purchased SHSs are common; (2) equipment is widely
available, inexpensive, but of questionable quality and shops do not provide detailed guidance
on installation; and (3) typical user-purchased SHS have severe technical shortcomings. These
findings are discussed in more detail below.
4.3.10.1 User-purchased SHS are common
In all four states visited in the course of this study, solar panels were frequently seen on houses
as the team drove to villages chosen to receive DRD SHS. It is difficult to estimate with
precision what portion of homes have user-purchased systems, but the author’s estimate is that
in villages along main roads in the areas visited at least 25% have SHS if they do not already
have electricity from power lines. In some areas (road side towns in Kayin state, for example) it
would not be surprising if the percentage exceeded 50%. In addition to fixed homes, solar
panels were frequently seen at temporary tent housing occupied by road construction workers.
Driving in southern Thanintharyi along the national highway, homes with solar panels basked in
the glow of LED lamps, while little yellow candles shine dimly from those without. Again, it
seemed at least 25% had solar.
One of the criteria for choosing which villages receive DRD SHS is that they household do not
have electricity already. Yet even in these “electricity poor” villages, among the households
visited 6 out of 24 (25%) were also using privately purchased solar home systems.
4.3.10.2 SHS shops
In all cities and market towns that the team passed through there were hardware shops selling
solar panels, wire, LED lights, and 12-volt batteries. These shops also sold hardware of all
kinds: shovels, buckets, pipes, twine, rat traps, clothes hangers, and carpentry tools.
In a small town northwest of Hpa An, Kayin State (coordinates: N17.18180, E97.66895) the
team stopped at one of at least six shops in the selling PV equipment. A sampling of products
and listed prices is shown below in Table 4. Note – these prices are as marked. In stores like
this bargaining is the norm so actual prices are likely to be somewhat lower. Even before
bargaining, prices of solar panels are below $0.70/watt peak.
Table 4: Some solar equipment and pricing at a hardware store in a small town northwest of Hpa An.
Item
Brand
Country
Size
26
Price
(Kyat)
PV panel
Tata
India
20 watt
18000
PV panel
Tata
India
38 watt
30000
PV panel
Tata
India
80 watt
60000
PV panel
Tata
India
100 watt
70000
LED
TV/DVD/MP3/USB
Sanook
Thailand
11.6" screen rated 1.5 Amperes at 43,000
12 volts (18 watt)
Inverter
No brand China
350 watt
18000
Inverter
No brand China
400 watt
20000
Inverter
No brand Myanmar
500 watt
50,000
Battery electrolyte
1.5 liter H2SO4 34%
1800
Battery distilled water
2 liter
600
Combined 2, 4, 6, 8, 12 volt.
Light-weight
33000
Battery
3K
Thailand
The hardware store selling these products did not provide guidance on how to correctly install
the system, and it appears that those who purchase systems are on their own to figure out how
to install them.
Figure 12: Solar PV products on display at a hardware shop in Kayin State
27
Solar panels and deep-cycle marine batteries were also sold in an automotive battery store
visited in Dawei. More expensive and higher quality solar equipment imported from Japan,
Taiwan, Europe and the USA were seen in specialty solar company storefronts in Hpa An and
Yangon.
4.3.10.3 Typical user-purchased SHS have severe technical shortcomings
4.3.10.3.1 No charge controllers
Of the privately purchased solar home systems inspected in the course of this research, only
one out of eight (12.5%) had a charge controller. It was not surprising, then, that chronically
overcharged and dry batteries were also encountered in these user-purchased solar home
systems.
4.3.10.3.2 Mismatch between solar panel and system voltage
A different interesting and pervasive problem encountered in user-purchased SHS is a severe
mismatch between solar panel voltage and battery voltage. Judging from the size of solar
panels seen on homes, many – if not most – appear to be large panels in the 200 to 250 watt
range. Industry-wide, solar panels larger than 140 watts are typically designed to be part of an
array on a grid-connected rooftop system or a solar farm.13 They are not designed to power 12volt solar home systems. The crucial difference is in the number of cells per panel. Solar panels
designed to charge 12-volt panels have 36 cells in series. Because of limitations in the size of
solar cells that can be produced, large solar panels typically have 60 or 72 cells in series.
A 60-cell solar panel will charge a 12-volt battery, but it does so very inefficiently because the
solar panel is forced by the battery voltage to operate far from its power point. In one system the
team measured, the battery voltage was resting at 11.6, while the open-circuit voltage of the
solar panel was 38.3 volts. A 240-watt 60-cell solar panel charging a 12-volt battery produces
roughly the same current a 136 watt 36-cell panel.
In order to properly use a 240 watt solar panel with a 12 volt battery, a maximum power point
tracking (MPPT) controller (or similar impedance matching device) is necessary. These are
available in Myanmar (sold by Earth Renewable Energy Company in Yangon) but are expensive
(over $200) and were never encountered in this field visit.
4.3.10.3.3 Wiring inadequate
SHS purchased privately in use in villages had wiring problems nearly identical to those detailed
in the DRD SHS descriptions in sections above including poor splices, lack of proper UV
resistant insulation, insecure wires, and undersized wires. In many cases, simple corrosionprone “alligator clip” connectors were used at battery terminals.
13
http://www.solar-electric.com/solar-panels-mounts-kits-accessories/solarpanels/hiposopa.html
28
4.3.10.3.4 Panel orientation, dust
Solar panels in private SHS were often installed at incorrect orientation and tilt angle. Especially
where SHS were installed along major roads, solar panels were often coated in thick dust.
Figure 13: Dusty solar panel on roof
4.4 DRD SHS supply chain
The research included meetings with six Myanmar companies that install (and in some cases
manufacture) solar home system equipment under the DRD program. Of these six companies,
five were in Yangon and one was in Hpa An (Moe Ko San). Table 5 below summarizes key
features of these companies.
Table 5: Statistics of Myanmar companies installing Solar Home Systems
Name of
Company
Moe Ko San
Solar
T & t Co. Ltd
Asia Solar
Earth
Renewable
Energy
Company
Type of
product/
service
offered
SHS and
mini-grids
Number
of staff
solar
sector
experience
Sourcing of
components
for DRD SHS
Revenues
(Thousand
US$/year)
2 years
SHS
built
to
date
780
33
SHS and
mini-grids.
Solar
street
lamps
From picosolar
products
to projects
> 10 kW
SHS, 1-3
kW
systems
Korea, China
160
200%
20
1.75 years
2722
China
80
1000%
170
5 years
7822
China
>1,000
>200%
25
12 years
3700
China
1,000
29
Expected
increase
FY2014-5
40%
Myanmar
Mahar Htun
SHS
6
involved
in PV.
(60 total)
None
0
SolaRiseSys
PV for
telecom,
SHS, minigrids,
lanterns
50
4 years
10208
Myanmar
company builds
systems for
them (OEM)
using parts from
China
China
233
not divulge
N/A
not divulge
Companies the team met with reflect a wide variety of experience, from complete beginners in
solar (Myanmar Mahar Htun) to veterans with more than ten years of experience (Earth
Renewable Energy Company) or over 100 employees (Asia Solar). Most companies play at
least the role of systems integrator, balancing cost and performance to select off-the-shelf
components for integration into a functioning SHS. Some, such as Asia Solar, go further than
this, designing their own charge control and inverter circuits, having them mass-manufactured in
China, and then assembling the circuit board components together with battery in a metal box.
All companies were expecting considerable growth in this 2014-5 fiscal year, and all stated they
would benefit from trade financing to ease cash flow constraints arising from the time lag
between ordering equipment and receiving payment for installed systems.
Overall, the companies visited appeared professional and serious, and as such provide an
excellent base for expanded quality SHS deployment in the country. Companies who are fairly
new to SHS would benefit from a beginning course on SHS best-practice design and
installation; while those at more advanced stages would benefit from a more advanced course
on the same topic.
4.5 ICT and solar electricity in Myanmar
Cell phone service is expanding rapidly in Myanmar, both in terms of new entrants and
especially in terms of expanded coverage. The consultant met with one cell phone operator
(Telenor) and two tower companies (Apollo Towers and Pan Asia Towers). Tower companies
build the towers and provide power (or will provide power) on contract to the cell phone
providers.
There are a number of areas where telecom and solar electricity intersect with interesting
opportunities for expansion of provision of electrical services to rural areas.
4.5.1 Solar hybrid systems to power towers
All cell phone towers need very high degrees of electricity service reliability, with uptime of 99.5
to 99.7%. Tower companies pay steep penalties if they are not able to meet these target
uptimes. For this reason, most towers – even those with grid connections – have diesel backup.
30
Off-grid towers typically have two diesel generators as well as batteries. Cell phone tower loads
are typically fairly constant, and vary from 1.2 kW to 3 kW depending on the type of equipment
installed. Delivering diesel fuel to remote sites, and providing maintenance to remote diesel
generators is very expensive. These relatively small loads and high maintenance costs make
PV-diesel hybrid systems a good business decision in many cases. Telenor is already using
hybrid PV-diesel systems. Apollo and Pan Asia’s equipment can accommodate PV and they are
either planning to incorporate PV (Pan Asia) or open to using PV (Apollo) if it lowers electricity
costs.
4.5.2 Cell phone towers as anchor customers for village mini-grids
Within in the next 5 years cell phone companies will be rapidly expanding. Telenor alone plans
to increase number of towers by 7000 to 8000, with more than half of these in rural areas. It is
not clear, however, how many of these were located close enough to villages to serve as the
anchor loads. Cell phone companies are interested in a model in which the cell phone tower is
an anchor customer and power is provided to villagers, but the cell phone companies
themselves will not take a proactive role in developing this as it is not their core business.
Telenor’s Head of Technology Strategy, Sian Tuang Tan, said that they have talked to a couple
companies but have yet to encounter one that seemed both interested in providing villagers with
power and that also understands the reliability requirements of Telenor's towers. He believes
the opportunity is there for a good mix, but so far no one has stepped forward with a good
proposal to them.
Tower companies are also interested, but at this point have not had the bandwidth to develop
business plans and address technology issues as they are focused entirely on meeting
ambitious tower construction schedules. Tower companies also raised the issue of lack of a
regulatory framework for mini-grids and small power producers. As part of Myanmar’s emerging
electricity regulatory framework there is a need for rules that provide detailed guidance on14:





how to legally develop mini-grids and sell electricity directly to retail customers;
what processes are required for licensing and registration;
how to set retail tariffs for sales to retail customers;
what options exist if the national grid expands into the service area of the mini-grid.
o Under what conditions can the mini-grid purchase electricity at wholesale from
the utility? What wholesale tariffs apply?
o Under what conditions can the mini-grid generator sell electricity to the main
grid? What feed-in tariffs apply?
who pays for interconnection costs and upgrades to the utility network, if required, for
interconnection.
14
For more on this issue, see: SPP Regulatory Framework Options in Myanmar: Final Report to the
International Finance Corporation. https://palangthai.files.wordpress.com/2014/11/finalreportmyanmarsppregulatoryoptions1.pdf
31
4.5.3 Solar PV for charging cell phones
Solar electricity is well-suited to charging cell phones, but cell phone companies and tower
companies that the author met are not planning any proactive cell-phone charging infrastructure
roll-out as it seems that villagers already procure their own solar panels to charge cell phones in
unelectrified areas (in addition to DRD’s work in this area).
4.5.4 Cell phone network to transmit mini-grid system performance data
Telenor's technology already accommodates necessary data transfer capability, and
presumably the situation is similar with competitors Ooredoo and MPT. All new Telenor towers
are equipped with at least "H" (2.75 G) and in populated areas, "H+" (3.5 G) data capability. The
electricity systems that power cell phone towers actively monitor diesel levels, battery voltage,
electricity consumption data, and send this at frequent intervals back to headquarters.
4.5.5 Electricity purchases via “Mobile money”
Telenor is planning to roll out mobile banking. Currently they are waiting for a license from
Ministry of Finance. Telenor has mobile banking in other places (Pakistan, Bangladesh) so no
new technology needs to be developed. Once the Ministry of Finance provides approval no
additional regulatory approvals should be necessary to apply mobile banking to automated
electricity purchases if another company wanted to use their platform to sell electricity services.
In all of the areas discussed above, telecom or tower companies have important roles to play in
potentially reaching segments of the rural electricity market. Even though these companies are
thoroughly engaged in expanding cell phone service as their core business, it will be important
to maintain open communications and encourage these companies to keep these rural
electrification considerations in mind as they build out infrastructure so that compatibilities are in
place when the time is ripe for them or other private sector entities to develop the areas
discussed above.
32
5 Recommendations and points for discussion
Based on the field visits and international practices, there are a number of recommendations (or
at least points of departure for further discussion) for improving the sustainability and scalability
of rural electrification through solar electricity under an expanded program. These cover a wide
range of areas, from policy, planning and regulation; to technical aspects of SHS design and
implementation; to financing and subsidies; and organizational capacity development.
5.1 Policy, planning and regulation
5.1.1 Include NEP geospatial plan in village selection
Activity: Adjust DRD SHS village selection process to include consideration of the National
Electrification Plan. Ideally Burmese versions of the appropriate NEP geospatial planning
documents should be shared with DRD staff at all levels from Naypyidaw down to the township
level. Moreover, a clear criterion for village eligibility vis-à-vis the NEP should be chosen, for
example DRD will only support SHS for villages not expected to be served by the grid within
three (five?) years. The township level committee, in coordination with the local office of ESE,
will serve as the primary filter to ensure that villages selected are consistent with the NEP and
grid expansion plans. But cross-checking at DRD district and state levels will be useful as well.
Reason needed: As the NEP was only recently completed, as yet it has no connection with the
selection of villages to participate in the DRD SHS program. This runs the risk of repeated
selection of villages that may be quickly connected to the main grid. Assuming that ESE’s grid
expansion follows the trajectory outlined in the NEP, then DRD’s SHS village selection process
should integrate NEP geospatial planning as well. Doing so will make better use of limited SHS
budgets. At the same time, the NEP should be regularly updated to include results from gridand off-grid expansion so that it is useful planning tool that reflects reality.
33
Figure 14: Roll-out of medium voltage (MV) grid in Kayin State in the NEP. Deployment of SHS should coordinate
with the NEP’s phased grid expansion. Source: Columbia Earth Institute, 2014. Electrification Planning for Myanmar:
Methodology and Sample Results for: Kayin State and Chin State. March 19, Nay Pyi Taw, Myanmar
5.1.2 Integrate sources of funding beyond DRD budget
Activity: Develop an institution or a financial account within DRD that can pool multiple sources
of funding earmarked for rural energy support. This would include funding for SHS as well as
community hydropower and other technologies and approaches related to expansion of energy
access in rural areas.
In a number of African countries (Tanzania, Mali, Senegal), this takes the form of a Rural
Energy Agency (REA), a semi-autonomous agency under the Ministry of Energy, that channels
government funds, fees from levies for rural electrification, and donor funds all in a transparent
way and uses these to further national goals of rural energy access. Many of these functions are
already performed by DRD, but DRD might find it useful to learn more about REAs to see if
there are useful practices and functions that may make sense for DRD to adopt.
Reason needed: Coordinated funding for rural energy access is necessary to avoid confusing
proliferation of projects and programs working at cross purposes, duplicating efforts in some
areas and leaving gaps in others. Donors are generally much more willing to contribute to a fund
when they see that it receives contributions from domestic sources and are confident that it is
well-managed.
34
5.2 Technical
5.2.1 Revise DRD SHS specifications to safeguard reliability and sustainability;
Activity: Reform the DRD SHS specifications to require equipment that meets certain quality
standards, and that the system is correctly installed.
Reason needed: Current DRD specifications are insufficient to ensure quality.
Any revision of the DRD specifications needs much more attention on quality standards. This
can be accomplished by requiring participating products to have been certified in World Bank
off-grid programs in other countries (e.g. the IDCOL program in Bangladesh), or that have
achieved some other appropriate international certification (e.g Global Lighting certification for
plug-and-play kits, IEC 61215 certification for PV modules, etc.). To encourage domestic SHS
industry and technology development, it is recommended that the World Bank support costs of
product testing (e.g. in the CQC laboratory in China) for local Myanmar products that pass initial
engineering tests and hold promise for meeting quality standards.
5.2.2 Revise DRD SHS system design to improve efficiency, reliability
Activity: improve SHS system design, increasing reliability and efficiency through removing
inverter, enabling reduction in PV, battery capacity
Reason needed: An inverter is not needed for lights, TV, cell phone charging, fan. A system
designed without an inverter can be smaller (because it no longer needs to overcome inverter
inefficiency) and the system is more reliable because small inexpensive inverters are
particularly failure-prone.
Table 6 below provides a recommended system configuration that provides roughly equivalent
services to existing DRD systems with more robust, but similar, equipment. A detailed critique of
existing specifications accompanied by a proposed improved SHS specification is included in
Appendix D. Note: fixing this “single system” specification would no longer make sense if the
DRD redesigns the SHS program to partially subsidize SHS across a broad range of capacities
(see 5.3.1 below).
Table 6: summary of suggested revised “Option B” specifications for DRD SHS based on component capacities. See
Appendix D for full version.
Qty
1
1
1
1
2
Item
Solar panel
Deep cycle
battery
Charge
Controller
LED lamp
LED lamps
Capacity
60 peak watts
60 Ah
Warranty
10 years
2 years
10 A
10 years
8 to 10 watts
3 to 5 watts
10 years
10 years
35
Notes
All inverters, charge controllers,
LED lights, solar panels, and
batteries must be accepted in
one of the following quality
control programs.
a.
Products certified for
use in a World Bank program
anywhere in the world
(currently Bangladesh’s IDCOL
Qty
Item
Capacity
Warranty
Wiring &
installation
All wiring copper stranded. All wiring
except wiring directly to lights
should be least 2.5 mm 2. Wiring to
LED lamps up to 5 watts must be at
least 0.5 mm2. Kits should
accommodate PV-to-controller wire
lengths of at least 8 meters.
Outdoor wiring must be UVresistant.
N/A
Notes
program and Global Lighting for
plug-and-play kits).
b.
Products having quality
marks issued by other agencies
should submit information on
these quality marks so that
DRD can decide whether they
are acceptable.
Installation consistent with “IEC
62257-9: Recommendations for
small renewable energy and
hybrid systems for rural
electrification”
5.3 Financing and subsidies
Financing and/or subsidy design has been an essential component for scale-up of off-grid
electricity services in a number of programs. Broadly, these can include subsidies to buy down
the cost to users of the SHS, and trade financing to installation companies to help cover cash
flow challenges of expanding installation business. In an expanded program, financing and
subsides may well draw on financial sources beyond those that the Myanmar government can
provide, highlighting the importance of an entity that can integrate multiple funding sources (see
5.1.2 above).
5.3.1 Redesign DRD SHS program to reduce subsidy amount, increase sustainability
Activity: Currently DRD tenders the installation of SHS in rural areas with 100% of the cost
covered by government budget and little assurances that companies will provide ongoing
support. Consider redesign of DRD SHS program to reduce subsidy amount, increase customer
choice, integrate with commercial sales of SHS, and enhance sustainability through
mechanisms that can help ensure maintenance is performed. Subsidy programs can be
designed to reduce gradually and ultimately disappear.
Reason needed: 100% give-away programs use up precious government funds quickly for
dissemination of equipment that can be paid for by household cash flows from reduced
expenditures on diesel and candles if customers are confident that the SHS is reliable. In
international experience, 100% give-away programs have problems that users (who received
the system for free) are less inclined to take very good care of the system than someone that
helped paid for it. In Myanmar the high prevalence of user-purchased SHS, and the substantial
36
savings on candles and oil lamps engendered by SHS already indicates a high willingness and
ability to pay for SHS.
A fundamental redesign requires answers to a number of difficult questions:
5.3.1.1 Should there be user subsidies? If so what amount?
Bangladesh’s IDCOL program, subsides were initially $90 per SHS. As of April 2014 they have
been reduced to $20 per SHS and are only provided for SHS up to 20 watts. In Tanzania, an
SNV/KfW program subsidizes lead-acid pico-solar kits at about $10 per watt. A South African
government-financed scheme subsidizes about 80% of the cost to users. The Lighting Global
program provides no subsidies to users, focusing instead on voluntary quality standards.
There are legitimate concerns that user subsidies undermine markets by creating unreasonable
expectations of price, by creating selection bias between subsidized and unsubsidized products,
and that when the subsidy goes away users are reluctant to invest. These concern need to be
balanced against the benefits of subsidies in reaching poorer populations that would be unable
to afford an unsubsidized product, and the ability of carefully implemented subsides to leverage
product quality.
In order to determine what levels (if any) of user subsidies are appropriate and (if appropriate) to
develop a targeted subsidy program, more research is needed on willingness to pay for SHS, on
the elasticity of demand with respect to price, and whether subsides are needed to reach the
targets of PV SHS usage by 2030.
5.3.1.2 Should there be subsidies for market development? If so what amount?
Subsidies for market development are subsidies directly to businesses to help pay cover the
cost of marketing and setting up a presence in rural markets that otherwise would be difficult to
serve commercially. Subsidized loans can also be made available to companies both for trade
finance (to cover gap in cash flow between purchasing components and final sale of equipmentsee 5.3.2 below) and refinancing micro-finance loans to consumers.
5.3.1.3 How should specifications be designed? Fixed capacity vs. service level, or none?
Under the current DRD program, specifications are fixed at a single system type: 80 watt PV, 65
Ah battery, 300 watt inverter, etc. This has the advantage of simplicity and standardization of
components, but locks all customers into a single system size regardless of their family size and
electrical needs.
One approach is to use specifications that simply set a minimum system size (20 watts PV
panel is used in IDCOL’s SHS program) and provide a subsidy appropriate for a system of that
size (e.g. US$25 subsidy in 2012, now $20). The 20 watt system in this example must provide
power for two 5 watt lamps plus a cell phone charger all for 4-5 hours of operation, and must
have sufficient battery storage for 3 days reserve. Until 2012 the $25 subsidy could be applied
to larger systems (50 watt, 85 watt PV). This arrangement helps ensure that poorer families
37
(who can only afford smaller systems) receive the highest subsidy when calculated as a
percentage of system cost and avoided providing higher subsidies to richer families who could
afford bigger systems.
Another approach is to set specifications for service level: e.g. sustainable rainy-season
operation of 3 lights each 180 lumen lights for 4 hrs/night. But leave the details of system design
open (with the exception of meeting quality standards) to allow innovation (including superefficient lights) that allows for downsizing of the solar panel and other components. While
service level specifications allow more flexibility, they may be difficult to verify in the field since
measuring lumen output of lamps requires special equipment, and since the measurements
must be taken over a number of days to ensure that the system has sufficient storage.
If the DRD decides to eliminate subsidies entirely, it may be appropriate to have no set
specifications, but rather rely on a “truth-in-advertising” type program like “Lighting Global” to
provide product testing and issuance of quality certifications for solar kits purchases directly by
users. Indeed, by communicating quality through a certification by a trusted organization,
Lighting Global or IDCOL’s list of approved products provides valuable information to all parties
(DRD, installers, users) about which products are high quality.
5.3.1.4 How to ensure long-term service follow-up
Equipment breaks. In order to ensure that a failure of a single component does not cascade into
the failure of the whole SHS, and in order to ensure that equipment warranties are meaningful,
consideration should be paid to arrangements that ensure long-term service follow up.
In Bangladesh’s IDCOL program, IDCOL operates a call center to address warranty failures.
Households experiencing problems with their SHS call the center directly. Complaints lodged to
IDCOL are recorded and forwarded to the installing partner organization (PO). The PO, in turn,
takes remedial measures directly with the household, and IDCOL has detailed information to
follow up if necessary.
5.3.2 Trade finance
Activity: Provide a trade finance facility to qualified solar companies. Considering delays in
payment that SHS companies report in getting paid, consider a loan tenor of at least up to 6
months.
Reason needed: Solar companies face considerable cash flow challenges between wholesale
equipment purchases and when they receive payment from the DRD.
5.4 Environmental and social
5.4.1 Battery recycling
Activity: More research is necessary to understand:
38




whether existing informal battery recycling incentivized by the commercial value of lead
in old batteries adequately ensures that SHS lead acid batteries are reliably removed
from villages when they fail;
the extent to which lead acid batteries from SHS as well as cars, trucks, motorcycles
are properly recycled;
what happens to acid from old batteries and whether it is a significant environmental
hazard;
whether recycling programs, if any, will be able to scale up in response to the increases
in old batteries that will eventually be the result of expanded scale-up of SHS in
Myanmar.
Research in Bangladesh suggests that informal sector recycling of SHS batteries is inadequate
and that most lead from batteries is released to the environment.15
If it is found that the battery disposal problem is not adequately addressed, DRD may need work
with township level to design programs to work with the private sector to ensure removal and
responsible recycling.
Battery recycling is made more complicated if Li-ion batteries (more common in pico-solar plug
& play kits) are deployed, as the techniques for lithium extraction and markets for recycled
lithium are probably beyond the reach of domestic Myanmar recyclers.
Reason needed: Lead is a potent neurotoxin and it is important to ensure that discarded SHS
batteries do not pollute the environment. Sulfuric acid from batteries is also a potential hazard.
5.5 Organizational process and institutional capacity
A variety of trainings are needed, including training for DRD (central, state, district and township
levels); trainings for companies and technicians that install SHS; and trainings for SHS users.
5.5.1 Training for DRD
Activity: Provide targeted training to the DRD on SHS. Topics to include:
 SHS principles of operation
 Main failure modes
 Running a SHS business (cash flow, marketing, engineering)
 Quality certification
 Specific information on how quality equipment and installation can help mitigate certain
failure modes.
 Designing and running a sustainable program
Batteiger, Alexander 2014. “Towards a Waste Management System for Solar Home Systems in
Bangladesh.” Symposium UC Berkeley April 10-12.
https://energypedia.info/wiki/Towards_a_Waste_Management_System_for_Solar_Home_Systems_in_Ba
ngladesh
15
39




How to select quality products -- incorporating experience or exposure to good quality
products
How to do better procurement
Outreach and information to consumers
SHS inspection and performance monitoring engineering
Reason needed: DRD is responsible for off-grid electrification but its engineering strengths lie
largely in civil and mechanical engineering, and DRD staff at all levels have little specific
knowledge in solar electricity. Training is needed at all levels -- central level, state level, district
level, and township level.
5.5.2 Develop training and certification for installers of solar home systems
Activity: Identify one or more training institutions and conducting a train-the-trainer course and
accreditation procedure to accredit institutions to teach a course of between 4 to 7 days on SHS
focusing on the particular model(s) that are installed under the DRD program. Technicians that
pass the training program would be certified to install systems that receive subsidies under an
expanded DRD program.
Tasks include developing a training manual; lectures; in-class exercises; practical sessions;
examinations and facilitators guide. The content would follow accepted established international
curriculum for SHS installer certification.
Some candidate topics for the DRD installer training:
1. How a SHS works
2. Basic electrical units (power, voltage, current, resistance)
3. AC vs. DC -- what they are, conversion efficiency, and why DC lights and TV are better
for SHS
4. Electrical consumption of different loads (LED lights, incandescent, TVs, DVDs, rice
cookers, etc.)
5. What a controller does and why you shouldn't bypass it
6. How to correctly orient a solar panel and why poor orientation compromises power
production.
7. Solar panels, shading, and dust
8. Battery safety
9. Maintenance and care of solar home systems
10. Solar home system vs. battery/kerosene economics
11. How to make good wire connections
a. Splices: avoid if possible, how to do them if necessary. Avoid especially splices
that will be exposed to rain and drips
b. Connections from PV panel
c. Connections to battery
12. Choosing proper wire sizes
13. Wire insulation – with particular focus on degredation from UV light and rain
40
14. Lead acid battery chemistry including discussion of sulfation and electrolysis of water
component of electrolyte when fully charged
15. Deep cycle vs. car batteries and why deep cycle batteries are much more appropriate for
SHS
16. What kind of labeling (e.g. brand name, country of origin, basic specs, certifications) you
should expect to see on SHS components and why to avoid those with no labels.
Reason needed: All installations visited in the course of this research had shortfalls that
compromise long-term safe and efficient SHS performance. These field visits indicate that the
companies involved in SHS (whether participating in the DRD program or not) would benefit
from systematic training of all installation technicians. In-person hands-on training helps provide
rigor for certified technicians.
5.5.3 Library of best-practice SHS videos
Activity: Create a library of 3-10 minute videos of best SHS practices calibrated to the Myanmar
context.
The content would draw from the list in 5.5.2 above. These video will have excellent graphics
and be very practical and simple, concise, and interesting. Videos will be available in Burmese
and other languages if appropriate. The videos would be developed and refined with using a
process that coordinates with, and follows topics closely aligned with, DRD installer trainings.
The process should incorporate at least one revision process to fine-tune content to the village
audience.
DVDs will distributed through a number of channels, including DRD staff at all levels (NPT,
state, district, township); companies involved in DRD SHS; provided to shops that sell PV SHS
privately for sale at low price or given away to customers; given to NGOs involved in rural
development; and other channels as appropriate. Upload videos to YouTube and Facebook.
Encourage copying.
Reason needed: A video format covering the content takes advantage of the fact that DVD
players and smart phones are already very common in villages, is a medium easily copied, and
helps create opportunities for best practices to be widely distributed.
5.5.4 Training booklet & videos for village SHS users
Activity: Create a simple pictorial booklet for best SHS user practices, calibrated to the Myanmar
context. This should have excellent graphics and be very practical and simple, concise, and
interesting. Create channels to disseminate videos of selected topics suitable for user education
(e.g. the first 10 topics in 5.5.2 above)
Consider broadcasting portions on TV channels that reach rural audiences as public service
announcements, similar to a successful "wash your hands" sanitation TV campaign that ran in
rural areas in the past few years.
41
Reasons needed: Poor understanding by system users of SHS installation, operation, and
maintenance severely compromises system performance. Booklet format is familiar and useable
even in unelectrified areas. A video format takes advantage of the fact that DVD players and
smart phones are already very common in villages.
5.5.5 Public exposure to quality products
Activity #1: Convene or facilitate exhibitions in which manufacturers can showcase quality
equipment;
Activity #2: Use multiple media channels (magazine and newspaper, internet, radio, TV, public
forums) to provide information on products that pass quality standards. Recommend draw from:
 IDCOL’s list of approved SHS components16; and
 Global Lighting’s website of products that have met Lighting Global Quality Standards. 17
Reason needed: Widespread use of reliable, affordable SHS will be more achievable if the
Myanmar private sector and the general public has information about the best products
available.
5.5.6 Provide assistance in development of business plans
Activity: Provide assistance to Myanmar companies to develop business
plans.
Reason needed: Myanmar businesses involved in solar electricity may
benefit from assistance in strategic planning including focus on
identifying business goals and markets, identifying finance needs and
options, and how to best to perform marketing.
5.5.7 Burmese smartphone SHS product review app
Activity: Create (if necessary) and market a Burmese-language smartphone app for solar product review and discussion. Could be modeled
after Amazon-type reviews, or “Consumr” App18.
Reason needed: Consumers have little information at their disposal to make important decisions
on solar equipment. Beyond word-of-mouth, there is no way for users to share experiences with
others regarding specific SHS and solar lantern products. Smart phones are common, even in
rural areas, and Facebook is particularly popular among Burmese people. The technology
platform exists for transparent user-generated reviews and information about products available
in the market place.
16
http://www.idcol.org/download/260275fd02d802e8ded266af02d51ea5.pdf
https://www.lightingglobal.org/products/?view=grid
18 http://www.consumr.com/
17
42
Appendix A: Survey form for DRD offices
1. Name of Government office:
2. Contact person:
3. Address:
4. Email:
5. Cell phone
6. Role in deployment of SHS:
7. Number of staff:
8. solar sector experience:
9. Number of solar home systems built to date in area of jurisdiction:
10. Procurement process:
11. Major issues:
43
Appendix B: Survey form for village household surveys
Field observations:
1. Date of visit
2. Time of visit
3. Customer name:
4. Customer address:
5. Date of installation:
6. Supply company name:
7. Installation company name:
8. Total number of households in village
9. Total number of households receiving SHS
10. Non-household buildings (e.g. schools, etc.) receiving SHS
11. How was SHS allocated (if not enough)
Customer Characterization
12. Number in household:
13. Type of housing:
14. Education levels and occupation of main income earners:
15. Average monthly household income:
16. Is income seasonal?
17. If income is seasonal, what months? (leave blank if not seasonal)
18. How was SHS obtained?
19. Was payment required to receive SHS?
20. SHS related expenses since installation (lights, new battery, etc.)?
21. What do you do when something in the system is not working?
22. Before getting SHS -- average monthly non-heat energy expenditures:
23. Before getting SHS – for what purposes were monthly non-heat energy expenditures
used?
24. After getting SHS -- average monthly non-heat energy expenditures:
25. After getting SHS – for what purposes what were monthly non-heat energy
expenditures?
Installation and operation
26. Is the system working correctly at present?
44
27. Does the householder have and understood the User’s Manual?
28. Is the householder adequately trained to maintain the system?
29. Is SHS used for productive purposes? (if no, skip to next section)
30. Productive use applications
31. Productive use frequency in the village
32. Owned and operated by men or women?
33. Estimate income generated.
User Feedback and Observations:
34. How many hours per day are three LEDs used?
35. How many hours per day are two LEDs used?
36. How many hours per day is one LED used?
37. How many LED lamps have failed?
38. How long does a typical LED lamp last?
39. How many hours per day is fluorescent tube light used?
40. How many fluorescent tube lamps have failed?
41. How long does a typical fluorescent tube light last?
42. What appliances if any are operated through the inverter?
43. How many hours per day are inverter-operated appliances are used on average?
44. How many times does the power has shut off by itself in an average in a month?
45. How many days does it remains shut off before it restarts?
46. How has life has changed due to availability of electricity
47. How did they pay for the SHS?
48. How are they paying for repairs and spare parts?
49. What do you do when something stops working?
50. How Supply and Installation Company is contacted in case of problems and how
company response has been?
51. What recommendations for improvement would the consumers propose?
52. User views on solar home system?
Technical SHS Characterization
Solar panel
53. Solar panel make:
45
54. Solar panel model:
55. Solar panel wattage:
56. Solar panel rated Voc
57. Solar panel rated Isc
58. Solar panel rated Vmp
59. Solar panel rated Imp
60. Solar panel serial no.
61. Global Solar Radiation in the Plane of Array
62. Weather conditions
63. Ambient temperature
64. Solar panel measured Voc
65. Solar panel measured Isc
66. Mounting structure
67. Solar panel orientation
68. Solar panel tilt
69. Solar panel observations
Battery
70. Type of battery
71. Brand
72. Model
73. Battery rated Ah
74. Terminal Volts (no load)
75. Cell Volts (if applicable)
76. Hydrometer readings (if flooded battery)
77. Voltage loss between controller to battery
78. current flow when measuring voltage loss (above)
79. battery enclosure
80. Age of battery (months):
81. battery observations
Light fixtures
82. Qty of LED lamps
46
83. AC or DC and volts
84. LED Lamp current (amps)
85. LED voltage loss from controller or inverter
86. LED observations
87. Qty of fluorescent lamps
88. AC or DC and volts
89. Fluorescent lamp current (amps)
90. Fluorescent lamp voltage loss from controller or inverter
91. Fluorescent lamp observations
Controller
92. Make
93. Model
94. Rating (amperage & voltage)
95. Includes LVD?
96. Describe monitoring (LED lights, meter, etc.)
97. LVD setpoint
98. High voltage disconnect setpoint
99. Controller observations
Inverter
100.
Make
101.
Model
102.
Rating (wattage)
103.
inverter observations
Outlet & wiring
104.
Number of outlets
105.
Describe outlets
106.
PV to controller wire size (mm2)
107.
PV to controller wire length (m)
108.
PV to controller wire type (e.g. stranded copper)
109.
PV to controller wire insulation
110.
Describe wiring penetration to house
47
111.
controller to battery wire size (mm2)
112.
controller to battery wire length (m)
113.
controller to battery type (e.g. stranded copper)
114.
controller to loads wire size (mm2)
115.
controller to battery wire lengths (m)
116.
controller to loads type (e.g. stranded copper)
117.
wiring interconnection type and condition
118.
wiring observations
Usage observations
119.
Is the system installed correctly without defects?
120.
Are there signs of excessive wear and tear suggesting premature failure in
components?
121.
Is there any indication of the consumer tampering or misusing the SHS?
48
Appendix C: Survey form for SHS businesses -- Supply Sector
Characterization and Assessment
SHS equipment suppliers, installers and maintenance survey questionnaire
1. Name of Company:
2. Owner (s) of the Company:
3. Address
:
4. Email:
5. Cell phone:
6. Type of product/ service offered and pricing
7. Number of staff:
8. solar sector experience:
9. Other areas of work (outside of solar home systems):
10. Number of solar home systems built to date:
11. Sourcing of components
12. Amount of domestic value addition
13. Assessment of quality of products, components and user documentation
14. How sales are made?
15. volume of sales (kyat/year)
16. Sales trends
17. principal customers
18. How warranties are honored and service and spares are provided?
19. Skill level and experience of staff
20. How staff are trained?
21. Major issues in the industry and support needed for improvement
49
Appendix D: Review of DRD SHS specifications
1
Background
The World Bank was asked to review a draft of specifications (see box 1) for solar home
systems to be deployed under the FY2014-5 DRD SHS deployment. The deployment is planned
to exceed 170,000 systems across 21 states/regions at an estimated to cost a total of
approximately 37,000 million kyats (US$38.5 million).
Box 2: DRD SHS specifications
Specification for Solar Household System(2014-2015)
1။
LED 3 Watt (2)No၊
20 Watt Lamp (1) No Household System
Limited Warranty
(1)
80-90 Watt Solar Pannel
- (1) No၊
(5-10)Years
(2)
Battery 12 Volt (65) Ah
- (1) N0၊
(1-2)Years
(3)
Controller (10)Ah(12V-24V)
- (1) No၊
(5-5)Years
(4)
Inverter 300 Watt
- (1) No၊
(5-5)Years
(5)
Cable (5)Meter
- (3) No
(6)
LED 3 Watt
- (2) No
(7)
20 Watt Lamp
- (1) No
(When -TV-21''Flat LCD is ON 20Watt Lamp has to be OFF)
( 8) Phone Charger
- (1) No
( 9) Total Cost
- (200000) Kyats
The specifications as written carry high risk of installation of solar home systems that perform
poorly in the long run due to improper design, improper installation, poor quality components
and materials, or combinations of all three.
The specifications should be improved considerably in two key areas.
1. Provide more detailed specifications to ensure quality: the specifications as written
should contain more information ensure quality from bidders.
2. System redesign to eliminate inverter: reliability and performance will be improved
considerably at zero or minimal cost increase by specifying efficient and reliable 12-volt
DC loads (LED lights, LED TV) thus enabling removal of the inverter entirely from the
system. This, in turn, provides much more cushion for the solar panel to perform in
suboptimal conditions (shading and dust encountered in villages). Already most SHS
companies encountered are providing DC LED lights, so in some ways the inverter is
50
already redundant. Money saved by removal of inverter should be used to focus on
quality components and quality installation including more attention to wiring.
This review is informed by experiences of a similar solar home system deployment by the Thai
government in 2004-519; procedures and standards followed in Bangladesh’s successful IDCOL
SHS deployment20, and simple Excel-based modeling of the DRD system design to validate
panel and battery size considering loads and reasonable assumptions for solar insolation.
Section 2 of this review discusses the existing DRD SHS specifications line by line, identifying
specifications that should be added or refined to improve quality and improve chances of longterm sustainable operation of the solar home systems. Section 3 presents a proposed improved
set of specifications which copies text liberally from the Bangladesh IDCOL “TSC Standards”
document21 with modifications to the Myanmar context.
2
Discussion of specifications22
2.1 System design revision
We used an excel spreadsheet (embedded below in Table 7 below) to check solar panel
wattage and battery capacity. We assumed a single 9 watt LED light is used 3 hours per night,
and two 3 Watt LED lights are used 5 hours per night, and the TV and cell phone charger are
used 1 and 2.5 hours per day respectively. Based on measurements in the field of actual short
circuit current compared to rated short circuit current, it appears that existing DRD SHS mostly
use modules that substantially underperform. Therefore, in modeling these systems we derated
the PV module substantially, assuming it only puts out 60% of its power. This may still be too
favorable, since most panels encountered in the field actually produced less than 50% of rated
current.
Threatened Sustainability: the Uncertain Future of Thailand’s Solar Home Systems. Andrew Lynch,
Chris Greacen, Salinee Tavaranan, Fredrik Bjarnegard. Paper commissioned by EU. 6 June 2006.
http://www.palangthai.org/docs/SHSReport6June06.doc
20 http://www.idcol.org/home/downloads
21 http://www.idcol.org/download/a86508e6f1ecc4bf3ac0f1c8ed6038cb.pdf
22 The first line: “1
LED 3 Watt (2)No 20 Watt Lamp (1) No Household System” is confusing as the
quantities appear to contradict quantities in later sections of the specifications. For example this line
appears to indicate one LED, but line 6 of the specification indicates two. In the remainder of this
document we assume that that this line is incorrect and loads are as specified in lines 6, 7 and 8.
19
51
Table 7: spreadsheet model of DRD SHS design assuming 80 watt solar panel and inverter
Qty
Load
Watts each
Watts total
Hours per day Watt hours
1 LED 9w
9
9
3
27
2 LED 3w
3
6
5
30
18
18
1
18
5
5
2.5
12.5
1 tv (12 inch with DVD)
1 cell phone charger
33
Totals
Battery efficiency
85%
Wiring efficiency
97%
Inverter efficiency (85%. If no inverter: 100%)
85%
Battery, wiring & inverter total efficiency
87.5
70.1%
Total adjusted watt hours per day
125
Nominal system voltage
12
Adjusted amp-hours per day
10.40
Peak Sun Hours
3.99
Amps of solar power required
2.61
Rated Imp (amps) per solar panel (80 watt: Imp = 4.5)
Solar panel derating
4.50
60%
Realistic Imp
2.70
Number of solar panels
0.97
Rounded up…
1
Isc per panel
5.06
Minimum controller current (amps) = 1.2 x Isc
6.07
Maximum number of days of autonomy
3
Max allowable depth of discharge
0.5
Battery ampere-hours
62
Based on this analysis:

A substantial revision will provide improved reliability, more efficiently, at lower cost.
Switching to 12-volt LED lighting only and using an efficient 12 volt LED TV allows the
system to eliminate the inverter and therefore use a smaller solar panel (60 watts) and
somewhat smaller battery (55 Ah). To build in a certain amount of over-sizing to account
for dust, unavoidable shading, and possible extended cloudy periods encountered in
villages, we derated the PV modules to 70% of rated output. Please see Table 8 below.
52
Table 8: spreadsheet model of improved design with no inverter and 50 watt solar panel.
Qty
Load
Watts each
Watts total
Hours per day Watt hours
1 LED 9w
9
9
3
27
2 LED 3w
3
6
5
30
18
18
1
18
5
5
2.5
12.5
1 tv (12 inch with DVD)
1 cell phone charger
33
Totals
Battery efficiency
87.5
85%
Wiring efficiency
97%
Inverter efficiency (85%. If no inverter: 100%)
100%
Total efficiency
82.5%
Total adjusted watt hours per day
106
Nominal system voltage
12
Adjusted amp-hours per day
8.84
Peak Sun Hours
3.99
Amps of solar power required
2.22
Rated Imp (amps) per solar panel (60 watt: Imp = 3.46)
Solar panel derating
3.46
70%
Realistic Imp
2.42
Number of solar panels
0.92
Rounded up…
1
Isc per panel
5.06
Minimum controller current (amps) = 1.2 x Isc
6.07
Maximum number of days of autonomy
3
Max allowable depth of discharge
0.5
Battery ampere-hours
53
2.2 Solar panel
Box 3: DRD solar panel specifications (exactly as written in DRD specifications)
(1) 80-90 Watt Solar Pannel
- (1) No၊
(5-10)Years
As discussed above, if system redesign can be accommodated by using LED lights and LED TV
and eliminating the inverter the solar panel can be downsized to 60 watts with no loss in
performance.
53
Five years warranty for a solar panel is far too low. While 10 years is acceptable, it should be
noted that warrantees for solar panels in USA and Europe are typically 10 years for materials
and workmanship and 20 to 25-year for power performance.
In addition to solar panel size and warranty, the section of the specifications for solar module
should include information about the module mounting structure, hardware used, mounting
angle, and directions on suitable locations for mounting module. Candidate text copied from the
Bangladesh IDCOL specifications are included in suggested revised specifications in Part 3.
Specifications should require PV panels that are either built to IEC standards (IEC 61215
certification for crystalline modules and IEC 61646 for thin-film modules) or are built in a facility
that makes modules that pass these standards. According to the US National Renewable
Energy Laboratory, “Modules that pass these qualification tests are much more likely to survive
in the field and not have design flaws that lead to infant mortality”23. If an IEC 61215 or 61646
certified module is not available then at the least the manufacturer should provide a
manufacturer’s compliance certification which states that a larger IEC-certified module is built
using same materials at same production line (with ISO 9001 certification).
Also acceptable would be to specify that if the product/component is already accepted for use in
an existing World-Bank-financed project, such as Bangladesh RERED, it can be sufficient
certification. Bangladesh has published such a list.24
Not requiring modules with these qualifications will likely mean that Myanmar’s SHS are built
with low-quality substandard modules that may fail within 10 years or less. Please see part 3 of
this document for suggested revisions.
2.3 Battery
Box 4: DRD battery specifications
Battery 12 Volt (65) Ah
- (1) N0၊
(1-2)Years
As discussed above, we recommend a downsized system with LED lights/TV and no inverter –
allowing a 55 Ah battery to provide up to 3 days of autonomy. IDCOL in Bangladesh requires 2
days of autonomy.25
Batteries are often the weak link in a solar home system and it is essential to have good quality.
Ideally these should be type-tested in a local laboratory as is done in Bangladesh.26 If these
batteries are available in Myanmar, it might be worthwhile considering simply adopting the
portion of this list that has batteries between 50 to 60 Ah.
23
http://www.nrel.gov/docs/fy12osti/54714.pdf
http://www.idcol.org/home/downloads/solar.
25 See section 1.2 of http://www.idcol.org/download/a86508e6f1ecc4bf3ac0f1c8ed6038cb.pdf
26 See http://www.idcol.org/download/260275fd02d802e8ded266af02d51ea5.pdf for a list of approved
batteries in Bangladesh.
24
54
Also, the battery warranty period (1 to 2 years) is low compared to Bangladesh (5 years).
Bangladesh requires tubular plate deep cycle batteries, and they have performance well and
their 5-year warranties are honored. If local batteries are used, these should be tested following
the procedure outlined in Appendix B.
Please see part 3 of this document for suggested revisions.
2.4 Controller
Box 5: DRD battery specifications
Controller (10)Ah(12V-24V) - (1) No၊
(5-5)Years
The controller is measured in amperes (A), not ampere-hours (Ah). The redesigned system
suggested in part 1 could save some money by using a smaller controller with current maximum
of only 5 A (although 10 A will also work).27 Since the SHS system has a 12 volt nominal system
voltage, there is no need for 12/24 volt controller – one with 12 V functionality alone is sufficient.
Controllers used in this program must include both a high and low voltage disconnect function to
protect against excessive battery charge and discharge. Specifications should include
specifications for voltage settings, low voltage disconnect settings and amperage, and
protection against reverse polarity and lightning.
Controllers are a very important, not very costly, and easily imported component. For this
reason, consider requiring controllers that have been either type-tested in the Bangladesh SHS
program28 or that can demonstrate compliance with PV GAP specifications.29
Please see part 3 of this document for suggested revisions.
2.5 Inverter
Box 6: DRD inverter specifications
Inverter 300 Watt
-
(1) No၊
(5-5)Years
Please consider removing the requirement for an inverter for the following reasons:
 12 volt loads including efficient LED lamps and LED TVs are widely
available: quality LED lamps are widely available designed for 12-volt operation.
If the intention of the inverter is to power a TV, consider that 12 volt LED TVs are
widely available and reliable. Efficiency of 12-volt TVs are higher and electronic
noise (buzz) lower than AC TVs. A 15.6” LED TV that won the Global LEAP
27
using criteria that controller current should be 1.25 times Isc
See extensive list at http://www.idcol.org/download/260275fd02d802e8ded266af02d51ea5.pdf
29 http://www.iecee.org/pv/pvrs/PVRS6A.pdf
28
55
competition costs less than $100 and consumes only 5.5 watts. This is available
from a Thai company very interested in exporting to Myamar.30 LED “laptop”
TV/DVD players with screen sizes 11 to 12 inches appear to be widely available
in rural Myanmar markets already imported from China or Thailand.

reliability: inverters fail (water intrusion, insects, lightning damage, reverse
polarity, etc). If the system relies on an inverter to provide AC power for lights,
then the failure of the inverter means that the house is without functioning lights.

safety: electricity from inverters at 230 volts can shock and kill. 12-volt electricity
has insufficient voltage to electrocute.

energy savings benefits: inverters are typically around 90% efficient when
operating near full load, with lower efficiencies at low loads. Even with no load,
inverters consume substantial idle current. Removing the inverter from the
system effectively provides an increase of 10% or more of end-use electricity,
allowing the same services to be provided with smaller PV module and battery
size.

cost savings (possible): removing inverter may lower costs, even after possibly
higher cost of 12-volt lighting.

users may still add their own inverter if they choose to: by providing a 12-volt
receptacle (see section 2.6 below), users may plug in their own inverter if they
chose to.
If the inverter is removed, then all remaining devices, switches, and wires must reflect this
choice.
Please see part 3 of this document for suggested revisions to the text.
2.6 Cable
Box 7: DRD wire specifications
Cable (5)Meter
-
(3) No
Correct choice of wire size and quality installation of wiring is absolutely essential for efficient
operation of the solar home system. The section on wiring should include discussion of
acceptable voltage drop (4% per circuit), wire type, wire lengths, and wire connection practices.
Wiring of a 12 volt receptacle should be included as well.
DRD may wish to consider requiring that installation, including all wiring, should be completed
following recommendations in 62257-9-6 Part 9-6: Selection of Photovoltaic Individual
Electrification Systems (PV-IES). Please see part 3 of this document for suggested revisions.
30
http://www.fosera.com/products/power-line/tv.html
56
2.7 LED light
Box 8: DRD LED light specifications
LED 3 Watt
-
(2) No
The LED light specification should specify minimum efficiency, voltage range, and warranty.
LED lights should have passed the Global Lighting minimum requirements31, or better, won the
Global LEAP awards.32
Having high quality LEDs is essential, as it helps ensure that the LED will provide efficient
lighting for years in service. These will be somewhat more expensive, but more than make up
for the higher price by lasting many times as long.
Please see part 3 of this document for suggested revisions.
2.8 20 watt fluorescent light
Box 9: DRD 20 watt fluorescent light specifications
20 Watt Lamp (1) No
(When -TV-21''Flat LCD is ON 20Watt Lamp has to be OFF)
The 12-volt 20 watt cfl should be replaced with a 12-volt 8-10 watt LED lamp. LED lights are
considerably more efficient and have longer lifetimes. The specifications should indicate
efficiency and warranty period. These are already used in some DRD SHS in Myanmar. See
remarks in 2.7 above.
Please see part 3 of this document for suggested revisions.
2.9 Phone charger
Box 10: DRD 20 watt fluorescent light specifications
( 8) Phone Charger
- (1) No
We suggest this be deleted – phone charger with appropriate phone-charging interface should
be purchased by user and plugged into the SHS 12-volt outlet. Or, better, the system
specification should require a USB port.
31
32
https://www.lightingglobal.org/activities/qa/standards/
http://www.cleanenergyministerial.org/Portals/2/pdfs/LEAP_Awards_2014BuyersGuide.pdf
57
2.10 Installation standards
Consider requiring that installation should follow the appropriate portions of IEC 62257-9:
Recommendations for small renewable energy and hybrid systems for rural electrification.
2.11 Overall system warranty
The specifications should include a system warranty that covers installation and workmanship.
This warranty is in addition to the equipment warranties of various components. Bangladesh has
a six months warranty against manufacturers’ defects on all system-integrated parts and labor
excluding fuses or end-use devices such as luminaries or lamps and seems a good choice for
Myanmar. Thailand’s SHS had a 2-year system warranty, but it was seldom enforced. In order
to ensure warranty compliance, there should be a mechanism, such as a performance
guarantee backed by a Bank Guarantee. If there is evidence that the warranty is not being
honored, the performance guarantee is triggered resulting in money owed to the bank.
Each system installed should include a warranty card and an operator manual delivered to the
householder at the time of installation with the warranty claim procedure explained. A simple
example warranty card example from Thailand is shown in Appendix A.
2.12 User’s manual
At the occasion of commissioning, each household receiving a SHSs should receive an
illustrated user’s manual to enable them to perform basic maintenance and understand
capabilities and limitations of the system. Installer should explain these issues verbally with
householder upon final inspection and commissioning of the installation. Details about what the
manual should cover are discussed in section 3 below.
2.13 Total cost
Box 11: DRD requirement for total cost
( 9) Total Cost -
(200000) Kyats
A price cap can be set, but considering the requirements discussed in this review the price may
rise to more than 200,000 kyats.
3
Candidate revised specification for solar home systems (2014-5)
3.1 Preamble
The following specifications are for solar home systems (SHS) deployed under the DRD SHS
program for fiscal year 2014-5. The system is designed to provide reliable electricity for two
small LED lights (>240 lumens each) for five hours per day; one large LED light (800 lumens or
more) for 3 hours per day; one LED TV (12 watts, 20 inch) two hours per day; and one cell
phone charger 2.5 hours per day. The specifications include important quality certifications that
help ensure that equipment is of good quality and will not fail prematurely.
58
3.2 solar module
i.
ii.
•
•
•
•
•
iii.
The solar home system should include one (1) module of certified rated capacity of
at least 60 watt (peak).
The following are applicable standards for PV modules:
International Electrotechnical Committee (IEC) 61215: Crystalline Silicon Terrestrial
PV Modules Design Qualification and Type Approval
IEC 61646: Thin Film Silicon Terrestrial PV Modules Design Qualification and Type
Approval IEC 60904-1: Photovoltaic Devices Part 1 Measurement of PV CurrentVoltage Characteristics
Institute of Electrical and Electronics Engineers (IEEE) 1262: Recommended
Practice for Qualification of Photovoltaic Modules
PV Global Approval Program (PV GAP) recommended standards are preferred.
If the chosen module is not IEC 61215 or 61646 certified, then in lieu of IEC 61215 or
61646 certification the manufacturer may provide a manufacturer’s compliance
certification which states that the proposed module comes from a factory that
manufactures a larger IEC 61215- or 61646-certified module and is using same
materials at same production line (with ISO 9001 certification).
Also acceptable is proof that the product/component is already accepted for use in
an existing World-Bank-financed project, such as Bangladesh RERED. See
http://www.idcol.org/download/260275fd02d802e8ded266af02d51ea5.pdf. The
module should carry at least a 10-year warranty performance warranty which states
that if power output drops to less than 90% of rated output, the module will be
replaced with a module of equal or higher capacity, at no cost to the owner.
iv.
Each module must be labeled indicating at a minimum: Manufacturer, Model
Number, Serial Number, Peak Watt Rating, Voltage and Current at peak power,
Open Circuit Voltage and Short Circuit Current of each module.
v.
The module must ensure waterproof sealing for the solar cells. Module must be
framed in such a way as to allow secure connection to the module mounting
structure.
vi.
Each module must be factory equipped with weatherproof junction box with terminal
strip that allows safe and long lasting wiring connection to the module.
vii.
The mounting structure will hold the photovoltaic module(s). The module(s) must be
mounted on a support structure made of corrosion resistant material that assures
stable and secure attachment.
viii.
The structure must be mounted at a fixed angle and oriented to maximize the useful
energy supplied to the user over the year (for Myanmar, the panel should be facing
south with a tilt angle measured from horizontal equal to the latitude of the
installation location (+/- 5 degrees).
ix.
The structure will incorporate corrosion resistant hardware for all external
connections.
x.
The modules can be roof or ground-mounted: In case of roof-mounted modules,
minimum clearance between the PV module and the roofing material must be at
least 20 cm. For pole mounted modules it is recommended that the module mounting
59
structure be supported on top of a pole of at least 5m height. The mounting structure
must be anchored to the building and not to the roofing material. For groundmounted modules, a metal, concrete or treated wood pole must be used with the
modules to be placed at the top of the pole. The modules must be at least 4 meters
off the ground and the pole must be anchored in concrete or tightly packed soil at
least one meter deep in the ground. The pole and mounting structure must be
sufficiently rigid to prevent twisting by the wind or if large birds alight on the module.
xi.
The panel should be mounted clear of vegetation, trees and structure so as to assure
that they are free of shadow throughout day light hours during each season of the
year.
3.3 Battery
i.
ii.
iii.
iv.
The SHS shall include a single 12-volt battery of capacity 50 to 60 Ah.
The battery shall either be on the list of approved batteries from the IDCOL program
in Bangladesh, or must pass the Interim Battery Acceptance Short Test Procedure
(below).
The battery shall have a 5-year limited warranty:
a. Battery capacity will not be less than 80 percent of the rated capacity over the
period for 5 years for systems. Cycle life of the battery (i.e., before its residual life
drops below 80 percent of the rated AH capacity), at 25 degree C must exceed
1500 cycles when discharged down to an average depth of discharge (DOD) of
70 percent at the discharge rate of 10 hours.
b. The maximum permissible self-discharge rate is 5 percent of rated capacity per
month at 25 deg C.
The battery must be housed in a vented compartment. All parts of the compartment
subject to battery acid contact must be acid resistant. This compartment must be
built strong enough to accommodate the weight of the battery. Access to the battery
compartment by children must be prevented.
3.4 Controller
i.
ii.
iii.
iv.
v.
vi.
vii.
The SHS shall include a charge controller with both high and low voltage disconnect
functions.
The charge controller input current rating must be greater than 120% of the module's
rated short circuit current.
Controller shall either be able to demonstrate compliance with PV GAP PVRS 6A
(http://www.iecee.org/pv/pvrs/PVRS6A.pdf ) recommended specifications for
controllers; or have been type-tested to comply with the IDCOL controller
requirements
(http://www.idcol.org/download/260275fd02d802e8ded266af02d51ea5.pdf), or has
been qualified for use in Bangaldesh RERED Project
The charge controller set points must be factory preset with the set points applicable
to the specified battery characteristics.
Charge Controllers should be dust and insect proof.
Maximum current draw of the controller, when no indicator LEDs are lit should not
exceed 20 mA and 50 mA with LED.
The model number, serial number, rated voltages and currents, and set points
should be printed on the visible side of the charge controller casing.
60
viii.
ix.
x.
xi.
xii.
xiii.
xiv.
xv.
xvi.
Battery, high voltage disconnect 14.3±0.2 volts (for lead acid batteries), or as
specified by the manufacturer. Charge controller specifications must include the type
of the battery to be used with it.
Reverse current leakage protection is recommended using logic-derived methods.
The SHS must be protected against damage caused by short circuit at panel
terminals and load terminals when battery is connected to the charge controller, and
reverse polarity of battery or panel connections. Over-current protection must be
provided. Lightning induced surge protection is recommended.
The load must be controlled by a low voltage disconnect (LVD) device. The LVD
must be capable of handling at least 150 percent of the maximum expected
continuous load (e.g., assuming all end use devices are simultaneously on). It should
be factory preset to disconnect and reconnect voltages corresponding to the safe
operation of the battery under ambient temperature conditions. For example, for a
lead acid battery, a disconnect voltage of 11.6 Vdc +/- 0.1 Vdc and reconnect voltage
of 12.6 Vdc +/- 0.2 Vdc is required.
Each charge controller should be capable of handling at least 120 percent of the
rated current at PV, battery and load terminals for at least for 1 hour without being
damaged. Overload of Charge Controller will be the actual current that exceeds
120% of the rated current.
Charge Controller should be capable of withstanding 25V at PV terminal when
battery and load is disconnected.
The technical specification of the charge controller must mention the input voltage
range (PV panel side), input current (PV panel side), battery nominal voltage, LVD
and HVD, rated output current (load side). The panel must have reverse polarity
protection, output short circuit and over load protection.
Efficiency of the charge controller should be at least 90%.
Warranty: Charge controller or energy meter should be replaced in case of any
performance deviation from the specifications mentioned above over the period of 5
years.
3.5 Inverter
Strongly consider removing inverter requirement as discussed in section 2.5.
(If DRD feels it is essential to keep the inverter, then use these specifications:
i.
SHS shall include 300 watt inverter
ii.
Modified sine wave or better AC output at 240 V and nominal 50 Hz is required.
iii.
Efficiency of the inverter shall be at least 90%.
iv.
Inverter shall be include short-circuit and overload protection and be protected from
dust and insects.
v.
Inverters should comply with PVGAP specifications.
3.6 Wiring
Wiring practices include the following:
i.
Stranded and flexible insulated copper wiring must be used. Sample of wires for the
sub circuits are as follows:
• From PV module to Charge controller : 2.5 sq. mm
• From Charge Controller to battery: 2.5 sq. mm
• From Charge Controller to socket outlet : 2.5 sq. mm
• From Charge Controller to all other loads (e.g. lights) : 0.5 sq. mm.
61
ii.
iii.
iv.
v.
vi.
vii.
viii.
Wiring should be sufficient to allow installation of solar panel within 8: meters of
controller. Wiring to lights should allow for installation of lights in separate rooms up
to 8 meters from controller.
Each light must have a separate switch
All wiring must be sized to keep line voltage losses to less than 3% including each
sub-circuit and to allow the circuit to operate within the rating of the wire. Cables
used for wiring must have three years of warranty.
For SHS permanently installed on a structure, all exposed wiring (with exception of
the module interconnects) must be in conduit or be firmly fastened to the building
structure. Wiring through roofing, walls and other structures must be protected
through the use of bushings. Wiring through roofing must form a waterproof seal.
Field-installed wiring must be joined using terminal strips or screw connectors.
Soldering or crimping in the field must be avoided if at all possible. Wire nuts are not
allowed. The rated current carrying capacity of the joint must not be less than the
circuit current rating. All connections must be made in junction boxes. Fittings for
lights, switches, and socket outlets may be used as junction boxes where practical.
A 12 Vdc socket outlet should be installed for a radio/CD player, TV or similar
appliance and must be rated to carry at least 5 amperes of DC current.
A USB port should be provided that is compatible with USB Battery Charging
standards.33
3.7 LED light
i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
The SHS must have two 3-watt LEDs and one LED of 8 to 10 watts, each controlled
by a separate wall-mounted switch. The larger lamp must provide area lighting.
LED lights used shall have passed Lighting Global
(https://www.lightingglobal.org/activities/qa/testmethods/) minimum requirements or,
better, have been chosen as winners in the Global LEAP awards.
Minimum lumen output of LED Lamp/lantern should be 80 lumen/watt.
LED should have 3 year warranty, and should provide minimum 80% of the initial
lumen output after 3 years (or 5000 hours considering the lower value of usage).
Color of LED light must be white.
Over the input voltage range of 11.6-14.4 V, input power of the LEDs must not vary
by more than 15% of the rated power.
Fixed LED lamp/lantern should not be placed at a height more 8 feet from the
ground.
Temperature of the heat sink of the driver circuit of the LED luminaries should be
tested and at still air condition, increase in temperature of the heat sink should not be
more than 20 Degree Celsius after one hour operation.
3.8 Installation standards
i.
33
Consider requiring that installation should follow appropriate portions of “IEC 622579: Recommendations for small renewable energy and hybrid systems for rural
electrification”.
http://en.wikipedia.org/wiki/USB#Mobile_device_charger_standards
62
3.9 Overall system warranty
i.
Each SHS should have a six-month overall system warranty against manufacturers’
defects on all system-integrated parts and labor excluding end-use devices such as
lamps.
3.10 User manual
i.
The solar home system (SHS) supplier must provide a User’s Manual intended for
the customers and will be included with each of the packaged systems.
ii.
The manual must be in Burmese. Sketches or graphics should be used to make the
manual easy to understand.
iii.
The manual should include the following:
a. How the SHS works: battery charging by the array, functions, battery low voltage
protection, and battery overcharge protection. The relationship between energy
available on a daily basis and sunlight conditions should be clearly and simply
explained.
b. A description of all user interactive hardware including disconnect switches and
status indicators.
c. Procedures for proper system operation, including a list of load limitations and
any problem loads. These procedures should include suggested operation,
including load conservation during periods of inclement weather, and/or a low
voltage disconnect event. The adverse effect of panel shading and the
importance of preventing it must be explained.
d. Basic maintenance to be done by user.
e. Any user maintenance items.
f.
Emergency shut down procedures and recommendations for extended periods of
system non-use.
g. A user trouble-shooting guide.
h. A block diagram showing the main components.
i.
Name address and telephone number of dealer/ supplier who is responsible for
warranty and service claims
j.
Name address and telephone number of DRD Office to be contacted if
dealer/supplier does not meet its obligations.
3.11 Qualified products.
i.
All inverters, charge controllers, LED lights, solar panels, and batteries must be
accepted in one of the following quality control programs.
a. Products certified for use in a World Bank program anywhere in the world.
63
b. Products with a valid Golden Sun Quality Mark issued by CQC China.
c. PVGAP Quality Mark issued by IECEE.
d. Products having quality marks issued by other agencies should submit
information on these quality marks so that DRD can decide whether they are
acceptable.
64
Appendix E: Sample warranty card
SOLAR HOME SYSTEM WARRANTY CLAIM
DATE CLAIM FILED:
CLAIM FILED BY:
Claimant Information
Date Claim Info Collected:
Name and Last Name:
Address Number:
Village:
Ward:
State / District:
Further Claimant Information:
Product Information
Malfunctioning System
Component(s):
1)
Serial Number
2)
3)
65
Brief Description of
Problem
CLAIM SENT TO:
CLAIM REPORT
COPIED TO:
Attn: (name of appropriate official)
Attn: (name)
Attn: (name)
(Institution)
(Address),
(City, State, Code)
(Institution)
(Address),
(City, State, Code)
(Institution)
(Address),
(City, State, Code)
Tel:
Fax:
Tel:
Fax:
Tel:
Fax:
66
Appendix F: Interim Battery Acceptance Short Test Procedure
Perform the test sequence as given below in Table 1 while maintaining the battery temperature
between 20-25 deg C.34 The tests must be conducted on 3 batteries that are randomly
selected, at a testing center acceptable to the PMO. Record the data in Table 2. If the test
results vary by more than 10% of each other, for the three batteries, an additional two batteries
should be tested to achieve better statistical significance. This test will take approximately 17
days to perform using automatic battery testing equipment.
Table 1 Interim Battery Acceptance Short Test Procedure
Current/voltage
Current/voltage
End-of-step Criteria
Remarks
Setting
Limit
Initial charge
+ I10
U=2.4 V/cell
Constant current charging
Initial charge
2.4 V/cell
+ I10
Duration 8 hours
Constant voltage charging.
1. C10 Test
1st discharge
-I10
U<1.8 V/cell
Rest Period
0A
I hour
Battery on open circuit
1st recharge
+ I10
U=2.4 V/cell
Constant current charging
1st recharge
2.4 V/cell
+ I10
Duration 8 hours
Constant voltage charging.
nd
2. C10 Test
2 discharge
-I10
U<1.8 V/cell
Rest Period
0A
I hour
Battery on open circuit
2nd recharge
+ I10
U=2.4 V/cell
Constant current charging
2nd recharge
2.4 V/cell
+ I10
Duration 8 hours
Constant voltage charging
3. C10 Test
3rd discharge
-I10
U<1.8 V/cell
Rest Period
0A
I hour
Battery on open circuit
3rd recharge
+ I10
U=2.4 V/cell
Constant current charging
3rd recharge
2.4 V/cell
+ I10
Duration 8 hours
Constant voltage charging
4. C10 Test
4th discharge
-I10
U<1.8 V/cell
4th recharge
+ I10
U=2.4 V/cell
Constant current charging
4th recharge
2.4 V/cell
+ I10
Gradient of current is Constant voltage charging
0 A/s, but maximum
36 hours35
th
Alternative for 4 recharge depending on availability of equipment
4th recharge
+ I10
U=2.4 V/cell
Constant current charging
4th recharge
2.4 V/cell
+ I10
I < 0.1 x I10
Constant voltage charging
4th recharge
0.1 x I10
Capacity charged in 4th recharge > 112% of capacity
discharged during 4th discharge
th
5. C10 Test
5 discharge
-I10
U<1.8 V/cell
Rest Period
0A
I hour
Battery on open circuit
5th recharge
+ I10
U=2.4 V/cell
Constant current charging
5th recharge
2.4 V/cell
+ I10
Duration 8 hours
Constant voltage charging
Capacity
Test No.
Step
34
Depending on the battery temperature (or ambient temperature in the laboratory during the tests) a correction of
the capacity is necessary if the temperature deviates by more than 3 deg Kelvin from 25°C. A correction factor of
0.6% per Kelvin is commonly used (see formula below). The formula can be applied for temperatures between 10
and 35°C. The pass criteria must be fulfilled for the temperature corrected values.
C1025C 
C10Tmeasured
1  0.006  (Tmeasured  25C )
35
Note that the end of the constant voltage charging is reached only when the battery current has not changed for
two hours. If this criterion has not been reached after 36 hours of the charging process, continue with the next step of
the test procedure.
67
Capacity
Test No.
6. C10 Test
Step
6. C20
discharge
Rest Period
6th recharge
6th recharge
7. C100
discharge
Rest Period
7th recharge
7th recharge
8. C5 discharge
Rest Period
8th recharge
8th recharge
9th discharge
Rest Period
9th recharge
9th recharge
Table 1 Interim Battery Acceptance Short Test Procedure
Current/voltage
Current/voltage
End-of-step Criteria
Setting
Limit
-0.5 x I10
U< 1.8 V/cell
0A
+ I10
2.4 V/cell
-0.1 x I10
0A
+ I10
2.4 V/cell
-2 x I10
0A
+ I10
2.4 V/cell
- I10
0A
+ I10
2.4 V/cell
+ I10
+ I10
+ I10
+ I10
Remarks
I hour
U=2.4 V/cell
Duration 8 hours
U< 1.8 V/cell
Battery on open circuit
Constant current charging
Constant voltage charging
I hour
U=2.4 V/cell
Duration 8 hours
U< 1.8 V/cell
I hour
U=2.4 V/cell
Duration 8 hours
U< 1.8 V/cell
1 hour
U=2.4 V/cell
Duration 8 hours
Battery on open circuit
Constant current charging
Constant voltage charging
Battery on open circuit
Constant current charging
Constant voltage charging
Battery on open circuit
Constant current charging
Constant voltage charging
TABLE 2 Interim Battery Acceptance Short Test
Battery Company:
Brand & Model
Number:
Samples obtained from:
Battery type:
(Select type)
Battery rated
voltage:
Date Samples collected:
Nominal Ah
Rating: C20
Nominal Ah Rating C10
Testing Period:
Start/end dates
Testing Engineer:
Approved by:
No. of samples.
Signature & Date:
Signature & Date:
For Flooded
battery: Select
one:
Discharge
Capacity Test
1. C10 Test
2. C10 Test
 Battery filled
onsite
 Battery obtained
fully charged
Discharging Current
(A)
End-of-Discharge
Voltage (V/cell)
Battery
Temperature
(deg C)
Measured & Corrected Capacity36
(Ah)
Average
Max
Pass Criteria
Min
1 x I10 =
1 x I10 =
36
Depending on the battery temperature (or ambient temperature in the laboratory during the tests) a
correction of the capacity is necessary if the temperature deviates by more than 3 degrees from 25°C. A
correction factor of 0.6% per degree is commonly used (see formula below). The formula is valid for
temperatures between 10 and 35°C. The pass criteria must be fulfilled for the temperature corrected values.
The capacity correction is as follows:
25C
10
C
C10Tmeasured

1  0.006  (Tmeasured  25C )
68
3.1 C10 Test
4 C10 Test
5. C10 Test
1 x I10 =
1 x I10 =
1 x I10 =
C20 Test
C100 Test
C5 Test
6. C10 Test
0.5 x I10 =
0.1 x I10 =
2 x I10 =
1 x I10 =
Measure Capacity ≥
100% Nominal
Capacity
Measured Capacity ≥
95% Nominal
Capacity
* Maximum and minimum values for the batteries (at least three) represented in “average” value.
Comments:
69